Net unrealized gains on investments Unrealized Gain (Loss) on Investments Less: Accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Statistical Measurement [Domain] Statistical Measurement [Domain] Investments Investment, Policy [Policy Text Block] Net realized gains on investments Realized Investment Gains (Losses) Non-Controlling Interests in Legacy Greenspring Entities Legacy Entities [Member] Legacy Entities Award Timing Predetermined Award Timing Predetermined [Flag] Remainder of FY2026 Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year Related Party Transaction [Axis] Related Party Transaction [Axis] Asset Class [Axis] Asset Class [Axis] Entity File Number Entity File Number Additional Paid-in Capital Additional Paid-in Capital [Member] O 2026 Q1 Dividends O 2026 Q1 Dividends [Member] O 2026 Q1 Dividends Deferred financing costs Payments of Financing Costs Greenspring Greenspring [Member] Greenspring Investment income Income (Loss) from Equity Method Investments Tabular List, Table Tabular List [Table Text Block] Total compensation and benefits Compensation And Benefits Expense Compensation And Benefits Expense Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] AUD Screen Rate Multiplied By Statutory Reserve Rate AUD Screen Rate Multiplied By Statutory Reserve Rate [Member] AUD Screen Rate Multiplied By Statutory Reserve Rate Schedule of Related Party Transactions Schedule of Related Party Transactions [Table Text Block] Discount rate Liability Classified Awards, Discount Rate Liability Classified Awards, Discount Rate Secured Overnight Financing Rate (SOFR) Secured Overnight Financing Rate (SOFR) [Member] Debt securities Debt Securities [Member] Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Fed Funds Effective Rate Overnight Index Swap Rate Fed Funds Effective Rate Overnight Index Swap Rate [Member] Basic (in dollars per share) Basic (in dollars per share) Earnings Per Share, Basic Adjustment to Compensation: Adjustment to Compensation [Axis] Related Party Transactions Related Party Transactions Disclosure [Text Block] Unrealized Unrealized performance fee-related compensation Performance Fee-Related Compensation Related to Carried Interest Allocation, Unrealized Performance Fee-Related Compensation Related to Carried Interest Allocation, Unrealized Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Number of shares reserved for future issuance (in shares) Common Stock, Capital Shares Reserved for Future Issuance Revenues Revenue from Contract with Customer [Text Block] Increase in deferred tax asset, equity-based compensation expense Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-Based Compensation Cost Subsidiary or Equity Method Investee, Sale of Stock by Subsidiary or Equity Investee [Table] Subsidiary or Equity Method Investee, Sale of Stock, Type [Table] Total other comprehensive loss Other comprehensive loss Other Comprehensive Income (Loss), Net of Tax Exchange Two Exchange Two [Member] Exchange Two Shares purchased (in shares) Stock Issued During Period, Shares, Employee Stock Purchase Plans Thereafter Finite-Lived Intangible Asset, Expected Amortization, after Year Four Finite-Lived Intangible Asset, Expected Amortization, after Year Four Class D exchange agreement, acceleration exchange, period Transaction Agreement, Maximum Period To Exchange Shares In Acceleration Exchange Transaction Agreement, Maximum Period To Exchange Shares In Acceleration Exchange Adjustment to Compensation, Amount Adjustment to Compensation Amount Equity method investment, total accrued carried interest allocation percentage Concentration Risk, Percentage Affiliated Entity Affiliated Entity [Member] Changes in unrealized gains included in earnings related to financial assets still held at the reporting date Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss) Number of classes of common stock outstanding Number Of Classes Of Common Stock Outstanding Number Of Classes Of Common Stock Outstanding Other assets and receivables Increase (Decrease) in Other Operating Assets Consolidation Consolidation, Policy [Policy Text Block] Equity-based compensation Share-Based Payment Arrangement, Noncash Expense Employee Stock Option Share-Based Payment Arrangement, Option [Member] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Consolidated funds Variable Interest Entity, Primary Beneficiary [Member] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Contributions to investments Payments to Acquire Equity Method Investments Dividends declared Dividends, Common Stock, Cash Total StepStone Group Inc. stockholders’ equity Equity, Attributable to Parent Measurement Frequency [Axis] Measurement Frequency [Axis] Insider Trading Policies and Procedures [Line Items] Class B Partnership Unit Class B Partnership Unit [Member] Class B Partnership Unit Equity-based compensation Liability based awards, expense Share-Based Payment Arrangement, Expense Number of cities for leased offices Lessee, Operating Lease, Number Of Cities Lessee, Operating Lease, Number Of Cities Equity issued for purchase of non-controlling interests Stock Issued For Purchase Of Non-Controlling Interests Stock Issued For Purchase Of Non-Controlling Interests Common stock, shares authorized (in shares) Common Stock, Shares Authorized Goodwill and Intangible Assets Disclosure [Abstract] S 2026 Q1 Dividends S 2026 Q1 Dividends [Member] S 2026 Q1 Dividends Total liabilities and stockholders’ equity Liabilities and Equity Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Fair Value, Recurring Fair Value, Recurring [Member] Interest rate in effect Line of Credit Facility, Interest Rate at Period End Unrealized gain on defined benefit plan, net Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Liabilities and stockholders’ equity Liabilities and Equity [Abstract] Due to affiliates Due to affiliates Accounts Payable, Other Cover [Abstract] Income-based incentive fees Income Based Incentive Fees [Member] Income Based Incentive Fees Maximum Maximum [Member] Finite-lived intangible assets, estimated useful lives Finite-Lived Intangible Asset, Useful Life Schedule of Equity Method Investments [Table] Equity Method Investment [Table] Less: Net income (loss) attributable to non-controlling interests Net Income (Loss) Attributable to Noncontrolling Interest Accounting Policies [Abstract] Intangibles, net Finite-Lived Intangible Assets, Net Schedule of Maturities of Operating Lease Liabilities Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Debt Instrument [Line Items] Debt Instrument [Line Items] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Carried interest allocations, SMAs Carried Interest Allocation, Separately Managed Accounts [Member] Carried Interest Allocation, Separately Managed Accounts Class C Partnership Unit Class C Partnership Unit [Member] Class C Partnership Unit Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Pay vs Performance Disclosure [Line Items] Lease liabilities Total operating lease liabilities Operating Lease, Liability Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Amounts receivable from StepStone Funds Other Receivables, StepStone Funds [Member] Other Receivables, StepStone Funds Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Revenue, carried interest allocation, minimum return levels required Revenue, Carried Interest Allocation, Minimum Return Levels Required Revenue, Carried Interest Allocation, Minimum Return Levels Required Income (loss) before income tax Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Entity Shell Company Entity Shell Company Number of additional exchanges Transaction Agreement, Number of Additional Annual Exchanges Transaction Agreement, Number of Additional Annual Exchanges Accounts payable, accrued expenses and other liabilities Accounts Payable and Other Accrued Liabilities Schedule of Long-Term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Legacy Greenspring performance fee-related compensation Legacy Performance Fee-Related Compensation Related to Carried Interest Allocation Legacy Performance Fee-Related Compensation Related to Carried Interest Allocation Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Schedule of Variable Interest Entities [Table] Variable Interest Entity [Table] Accounts payable, accrued expenses and other liabilities Increase (Decrease) in Other Accounts Payable and Accrued Liabilities Redemption of redeemable non-controlling interests Redemptions of redeemable non-controlling interests in Consolidated Funds Payments for Repurchase of Redeemable Noncontrolling Interest Statement of Cash Flows [Abstract] Company Selected Measure Amount Company Selected Measure Amount FY2029 Lessee, Operating Lease, Liability, to be Paid, Year Three Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Line of Credit Facility [Table] Line of Credit Facility [Table] Advisory and other services Management And Advisory Fees, Net, Advisory And Other Services [Member] Management And Advisory Fees, Net, Advisory And Other Services Comprehensive income (loss) attributable to StepStone Group Inc. Comprehensive Income (Loss), Net of Tax, Attributable to Parent Vesting of Class B2 units and issuance of corresponding Class B common stock at par value Stock Issued During Period, Value, Restricted Stock Award, Net of Shares Withheld For Employee Taxes Stock Issued During Period, Value, Restricted Stock Award, Net of Shares Withheld For Employee Taxes Name Measure Name Letters of credit Letter of Credit [Member] Purchase of non-controlling interests Payments to Noncontrolling Interests Non-Controlling Interests in the Partnership Partnership Of Subsidiary [Member] Partnership Of Subsidiary Swiss Average Rate Overnight Swiss Average Rate Overnight [Member] Swiss Average Rate Overnight Due from affiliates Other Receivables Increase (Decrease) in Stockholders' Equity [Roll Forward] Equity, Attributable to Noncontrolling Interest [Roll Forward] Schedule of Changes in the Fair Value of Level III Financial Instruments Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Purchases of investments of Consolidated Funds Investments of Consolidated Funds, Cost Investments of Consolidated Funds, Cost Document Fiscal Period Focus Document Fiscal Period Focus Realized Carried Interest Allocation, Realized [Member] Carried Interest Allocation, Realized Award Timing Method Award Timing Method [Text Block] Class D Partnership Units Class D Partnership Units [Member] Class D Partnership Units Award Type [Axis] Award Type [Axis] Realized Performance Fee-Related Compensation Related to Carried Interest Allocation, Realized Performance Fee-Related Compensation Related to Carried Interest Allocation, Realized Foreign currency translation adjustments Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Debt obligations outstanding Total debt obligations Long-Term Debt Total assets Assets Assets Carried interest, contingent repayment obligations Equity Method Investment, Carried Interest Allocations, Maximum Amount Subject To Contingent Repayment Equity Method Investment, Carried Interest Allocations, Maximum Amount Subject To Contingent Repayment Investment, Name [Domain] Investment, Name [Domain] Schedule of Unvested Restricted Stock Units Activity Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] FY2027 Finite-Lived Intangible Asset, Expected Amortization, Year One Trading Symbol Trading Symbol FY2030 Lessee, Operating Lease, Liability, to be Paid, Year Four Vested (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Restricted Cash Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Legacy carried interest allocation as percentage of cumulative fund or account performance Revenue, Legacy Carried Interest Allocation As Percentage Of Cumulative Fund Or Account Performance Revenue, Legacy Carried Interest Allocation As Percentage Of Cumulative Fund Or Account Performance Performance fees Performance Fees [Member] Performance Fees Geographical [Domain] Geographical [Domain] Income Taxes Income Tax, Policy [Policy Text Block] Entity Address, City or Town Entity Address, City or Town Variable Interest Entity, Not Primary Beneficiary, Subsidiaries Variable Interest Entity, Not Primary Beneficiary, Subsidiaries [Member] Variable Interest Entity, Not Primary Beneficiary, Subsidiaries Cash flows from operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] SMAs Management And Advisory Fees, Net, Separately Managed Accounts [Member] Management And Advisory Fees, Net, Separately Managed Accounts Effect of foreign currency exchange rate changes Effect of Exchange Rate on Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Concentration Risk Type [Axis] Concentration Risk Type [Axis] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Restricted Stock Units (RSUs) Restricted Stock Units (RSUs) [Member] Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Cash paid for amounts included in the measurement of lease liabilities: Cash Paid For Amounts Included In The Measurement Of Lease Liabilities [Abstract] Cash Paid For Amounts Included In The Measurement Of Lease Liabilities Management and advisory fees, net Management And Advisory Fees, Net [Member] Management And Advisory Fees, Net Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items] Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items] General Partner General Partner [Member] The Exchange 2025 Exchange [Member] 2025 Exchange FY2030 Finite-Lived Intangible Asset, Expected Amortization, Year Four Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Entity Emerging Growth Company Entity Emerging Growth Company Dividend (in dollars per share) Common Stock, Dividends, Per Share, Declared Amounts receivable from employees Other Receivables, Employees [Member] Other Receivables, Employees Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Units issued for purchase of asset class non-controlling interests (in shares) Stockholders' Equity, Units Issued For Purchase Of Asset Class Noncontrolling Interest Stockholders' Equity, Units Issued For Purchase Of Asset Class Noncontrolling Interest Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Less: Debt issuance costs Debt Issuance Costs, Net Level II Fair Value, Inputs, Level 2 [Member] SRA SRA [Member] SRA Total equity method investments Equity Method Investments Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Business Combination [Domain] Business Combination [Domain] Class C Common Stock Common Class C [Member] Common stock, shares outstanding (in shares) Common stock, shares outstanding, beginning balance (in shares) Common stock, shares outstanding, ending balance (in shares) Common Stock, Shares, Outstanding Schedule of Common Stock Outstanding [Roll Forward] Schedule of Common Stock Outstanding [Roll Forward] Schedule of Common Stock Outstanding Unrealized carried interest allocations and investment income Carried Interest Allocation And Investment Income, Unrealized Gain (Loss) Carried Interest Allocation And Investment Income, Unrealized Gain (Loss) Compensation and benefits: Income Statement Compensation Expense Items [Abstract] PEO PEO [Member] Schedule of Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Non-cash operating, investing, and financing activities: Noncash Investing and Financing Items [Abstract] Interest income Investment Income, Interest Increase (decrease) in valuation allowance Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount Cash-based compensation, expense Deferred Compensation Arrangement with Individual, Compensation Expense United States UNITED STATES Changes in operating assets and liabilities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Schedule of Product Information [Table] Nature of Operation, Product Information, Concentration of Risk [Table] Schedule of Future Amortization of Finite-lived Intangible Assets Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Retained Earnings (Accumulated Deficit) Retained Earnings [Member] Legacy Greenspring carried interest allocations Legacy Carried Interest Allocation [Member] Legacy Carried Interest Allocation Number of RSUs and PRSU Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Restatement Determination Date Restatement Determination Date Share-Based Payment Arrangement [Abstract] Cash, cash equivalents and restricted cash at beginning of period Cash, cash equivalents and restricted cash at end of period Total cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Income Statement [Abstract] Income tax expense (benefit) Income Tax Expense (Benefit) Basis spread on variable interest rate Debt Instrument, Basis Spread on Variable Rate Class B Common Stock Class B units Common Class B [Member] Sale of Stock [Domain] Sale of Stock [Domain] New York Federal Reserve Bank Rate New York Federal Reserve Bank Rate [Member] New York Federal Reserve Bank Rate Other assets and receivables Other Assets Balance, beginning of period: Balance, end of period: Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Intangibles, net Intangible Assets, Net (Excluding Goodwill) Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Product and Service [Domain] Product and Service [Domain] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Due to related parties, tax receivable agreements Due To Related Parties, Tax Receivable Agreements Due To Related Parties, Tax Receivable Agreements Net income (loss) Net income (loss) Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] One Investment One Investment [Member] One Investment Legacy carried interest allocation, SMAs Legacy Carried Interest Allocation, Separately Managed Accounts [Member] Legacy Carried Interest Allocation, Separately Managed Accounts Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] City Area Code City Area Code Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] All Trading Arrangements All Trading Arrangements [Member] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Redemption price, percentage Debt Instrument, Redemption Price, Percentage Beginning balance (in shares) Ending balance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Commitments and Contingencies Disclosure [Abstract] Proceeds from revolving credit facility Proceeds from Long-Term Lines of Credit Cash flows from investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] General, administrative and other General and Administrative Expense Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Net cash provided by operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Legacy Greenspring investment income (loss) Legacy Greenspring investment income (loss) Legacy Investment Income Legacy Investment Income Debt instrument, term Debt Instrument, Term Related Party Transactions [Abstract] Equity Method Investments and Joint Ventures [Abstract] Share exchange, shares exchanged (in shares) Stockholders' Equity, Share Exchange, Shares Exchanged Stockholders' Equity, Share Exchange, Shares Exchanged Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Subsequent Event Subsequent Event [Member] Total lease cost Lease, Cost Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Other liabilities Other Liabilities Goodwill Goodwill Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Summary of Components of Lease Expense and Supplemental Cash Flow Information Lease, Cost [Table Text Block] PEO Total Compensation Amount PEO Total Compensation Amount Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Total investment income of Consolidated Funds Gain (Loss) on Investments Percentage of Total Investments as of Investments of Consolidated Funds, Percent Of Total Investments Investments of Consolidated Funds, Percent Of Total Investments Thereafter Lessee, Operating Lease, Liability, to be Paid, After Year Four Lessee, Operating Lease, Liability, to be Paid, After Year Four Remainder of FY2026 Finite-Lived Intangible Asset, Expected Amortization, Remainder of Fiscal Year Numerator: Net Income (Loss) Available to Common Stockholders, Diluted [Abstract] Equity Components [Axis] Equity Components [Axis] Transfers out of Level III Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3 Non-U.S. countries Non-US [Member] Sublease income Sublease Income Share exchange, shares issued (in shares) Stockholders' Equity, Share Exchange, Shares Issued Stockholders' Equity, Share Exchange, Shares Issued Class Of Partnership Unit [Axis] Class Of Partnership Unit [Axis] Class Of Partnership Unit Unrealized investment income of Consolidated Funds Unrealized Investment Gain (Loss) From Consolidated Funds Unrealized Investment Gain (Loss) From Consolidated Funds Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Number of reportable segments Number of Reportable Segments Excluding Consolidated Funds Excluding Consolidated Funds [Member] Excluding Consolidated Funds Supplemental disclosures: Supplemental Cash Flow Information [Abstract] Goodwill, impairment loss Goodwill, Impaired, Accumulated Impairment Loss Variable Interest Entities Variable Interest Entity Disclosure [Text Block] Other Performance Measure, Amount Other Performance Measure, Amount Entity Address, State or Province Entity Address, State or Province Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Security, Excluded EPS Calculation [Table] Unrealized Carried Interest Allocation, Unrealized [Member] Carried Interest Allocation, Unrealized Fair Value Measurements Fair Value Measurement, Policy [Policy Text Block] Percentage of total net cash savings retained Incremental Net Cash Tax Savings Due To Exchanging Limited Partners, Benefit Retained, Percent Incremental Net Cash Tax Savings Due To Exchanging Limited Partners, Benefit Retained, Percent Deferred Tax Asset [Domain] Deferred Tax Asset [Domain] Related Party [Domain] Related and Nonrelated Parties [Domain] Purchases of investments of Consolidated Funds Payments To Acquire Consolidated Funds Payments To Acquire Consolidated Funds EURIBOR Rate Multiplied By Statutory Reserve Rate Euro Interbank Offer Rate Multiplied By Statutory Reserve Rate [Member] Euro Interbank Offer Rate Multiplied By Statutory Reserve Rate Individual: Individual [Axis] Restricted cash Restricted Cash Net income (loss) per share of Class A common stock: Earnings Per Share Reconciliation [Abstract] Dividends paid to common stockholders Payments of Ordinary Dividends, Common Stock Proceeds from capital contributions from non-controlling interests Proceeds From Capital Contributions From Non-Controlling Interests Proceeds From Capital Contributions From Non-Controlling Interests Entities [Table] Entities [Table] Investments: Investments [Abstract] Net cash used in investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Annual portion of equity interests to be exchanged Stockholder's Equity, Transaction Agreement, Annual Portion Of Equity Interests To Be Exchanged Stockholder's Equity, Transaction Agreement, Annual Portion Of Equity Interests To Be Exchanged Contributions from redeemable non-controlling interests in Consolidated Funds Proceeds from Noncontrolling Interests Document Fiscal Year Focus Document Fiscal Year Focus Maximum exposure to loss Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Less: Comprehensive income attributable to redeemable non-controlling interests Comprehensive Income (Loss), Net Of Tax, Redeemable Noncontrolling Interest Comprehensive Income (Loss), Net Of Tax, Redeemable Noncontrolling Interest Lease right-of-use assets, net Operating Lease, Right-of-Use Asset Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Investments of consolidated funds Partnership and LLC interests Investments of Consolidated Funds Investments of Consolidated Funds Effective tax rate Effective Income Tax Rate Reconciliation, Percent Cash-based compensation Compensation Expense, Cash Based Compensation And Benefits Compensation Expense, Cash Based Compensation And Benefits Entity Interactive Data Current Entity Interactive Data Current Operating lease cost Operating Lease, Cost Contributed capital Partners' Capital Account, Contributions Unrecognized non-cash compensation, period of recognition Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Equity [Abstract] Amounts receivable from loans Other Receivables, Loans [Member] Other Receivables, Loans Intangibles and Goodwill Goodwill and Intangible Assets, Policy [Policy Text Block] Contingent consideration paid Business Combination, Contingent Consideration, Amount Paid Business Combination, Contingent Consideration, Amount Paid Segment Reporting Segment Reporting Disclosure [Text Block] Minimum amount of prepayment, percentage Debt Instrument, Minimum Amount Of Prepayment, Percentage Debt Instrument, Minimum Amount Of Prepayment, Percentage Management contracts Management Contracts [Member] Management Contracts Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Carried interest allocation, focused commingled funds Carried Interest Allocation, Focused Commingled Funds [Member] Carried Interest Allocation, Focused Commingled Funds Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Incentive fees as percentage of profits Revenue From Contract With Customer, Incentive Fees As Percentage Of Net Investment Income Revenue From Contract With Customer, Incentive Fees As Percentage Of Net Investment Income Other Commitments [Line Items] Other Commitments [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] StepStone Group LP StepStone Group LP [Member] StepStone Group LP Ownership [Domain] Ownership [Domain] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Minimum management fees payable Debt Instrument, Covenants, Minimum Management Fees Payable Debt Instrument, Covenants, Minimum Management Fees Payable Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Amortization of intangible assets Amortization of Intangible Assets Leases Lessee, Leases [Policy Text Block] Legacy carried interest allocation, focused comingled funds Legacy Carried Interest Allocation, Focused Commingled Funds [Member] Legacy Carried Interest Allocation, Focused Commingled Funds Deferred income tax assets Deferred Income Tax Assets, Net Schedule of Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Investment income of Consolidated Funds Income (Loss) From Consolidated Funds Income (Loss) From Consolidated Funds Depreciation and amortization Depreciation, Depletion and Amortization Entity Central Index Key Entity Central Index Key Noncontrolling Interest In Consolidated Funds Noncontrolling Interest In Consolidated Funds [Member] Noncontrolling Interest In Consolidated Funds PEO Name PEO Name Total revenues Revenues Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Cash-based incentive awards granted, value Deferred Compensation Arrangement with Individual, Cash Award Granted, Amount Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Revolving credit facility Revolving Credit Facility [Member] Liability Classified Award Liability Classified Award [Member] Liability Classified Award Amortization of deferred financing costs Deferred Debt Issuance Cost, Writeoff Changes to uncertain tax positions Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit Arrangement Duration Trading Arrangement Duration Amounts payable to non-controlling interest holders in connection with Tax Receivable Agreements Other Liabilities, Non-Controlling Interest Holders due to Tax Receivable Agreements [Member] Other Liabilities, Non-Controlling Interest Holders due to Tax Receivable Agreements SRE SRE [Member] SRE Exercise Price Award Exercise Price Share exchange ratio Stockholder's Equity, Share Exchange Ratio Stockholder's Equity, Share Exchange Ratio Entity Filer Category Entity Filer Category Local Phone Number Local Phone Number Class of Stock [Domain] Class of Stock [Domain] Separately Managed Account Concentration Risk Separately Managed Account Concentration Risk [Member] Separately Managed Account Concentration Risk Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Valuation Allowance by Deferred Tax Asset [Axis] Valuation Allowance by Deferred Tax Asset [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Equity-Based Compensation Share-Based Payment Arrangement [Text Block] Changes in operating assets and liabilities of Consolidated Funds: Adjustments To Reconcile Net Income (Loss) To Cash Provided By (Used In) Operating Activities, Consolidated Funds [Abstract] Adjustments To Reconcile Net Income (Loss) To Cash Provided By (Used In) Operating Activities, Consolidated Funds Unfunded capital commitments Off-Balance-Sheet, Credit Loss, Liability Conversion basis Conversion Of Stock, Conversion Basis Conversion Of Stock, Conversion Basis Assets Assets [Abstract] Credit Facility [Axis] Credit Facility [Axis] Focused commingled funds Management And Advisory Fees, Net, Focused Commingled Funds [Member] Management And Advisory Fees, Net, Focused Commingled Funds Less: Comprehensive income attributable to non-controlling interests Comprehensive Income (Loss), Net of Tax, Attributable to Nonredeemable Noncontrolling Interest Comprehensive Income (Loss), Net of Tax, Attributable to Nonredeemable Noncontrolling Interest Underlying Security Market Price Change Underlying Security Market Price Change, Percent FY2029 Finite-Lived Intangible Asset, Expected Amortization, Year Three Decrease in deferred tax assets, transaction agreements Increase (Decrease) in Deferred Tax Asset, Transaction Agreements Increase (Decrease) in Deferred Tax Asset, Transaction Agreements Debt Instrument [Axis] Debt Instrument [Axis] Forfeited (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Fair Value Measurements Fair Value Disclosures [Text Block] Legacy Funds Legacy Funds [Member] Legacy Funds Credit Facility [Domain] Credit Facility [Domain] Intangible assets, gross Finite-Lived Intangible Assets, Gross Redemption of redeemable non-controlling interests in subsidiaries Redeemable Noncontrolling Interest, Increase From Redemption Redeemable Noncontrolling Interest, Increase From Redemption Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Entity Address, Address Line One Entity Address, Address Line One Entity Address, Address Line Two Entity Address, Address Line Two Accumulated Other Comprehensive Income Accumulated other comprehensive income AOCI Attributable to Parent [Member] Senior notes, interest rate Debt Instrument, Interest Rate, Stated Percentage Investment, Name [Axis] Investment, Name [Axis] Earn-out amount Business Combination, Contingent Consideration, Change in Range of Outcomes, Liability, Maximum, Increase (Decrease) Investments [Domain] Investments [Domain] Redeemable non-controlling interests in Consolidated Funds Beginning balance Ending balance Redeemable Noncontrolling Interest, Equity, Carrying Amount Ownership [Axis] Ownership [Axis] Schedule of Rollforward of the Company's Shares of Common Stock Outstanding Since IPO Schedule of Stock by Class [Table Text Block] Legacy Greenspring investments in funds Legacy Investments In Funds Legacy Investments In Funds Fair Value as of Grant Date Award Grant Date Fair Value Fees and accounts receivable Accounts Receivable, after Allowance for Credit Loss Entity Registrant Name Entity Registrant Name SMAs Incentive Fees, Separately Managed Accounts [Member] Incentive Fees, Separately Managed Accounts Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Assumed vesting of shares (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Maximum share purchase, value Share-Based Compensation Arrangement by Share-Based Payment Award, Maximum Number of Shares Per Employee, Value Share-Based Compensation Arrangement by Share-Based Payment Award, Maximum Number of Shares Per Employee, Value Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Total expenses Costs and Expenses Unrecognized non-cash compensation Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Distributions payable to certain employee equity holders of consolidated subsidiaries Related Party Transaction [Line Items] Partnership and LLC interests Partnership And LLC Interests [Member] Partnership And LLC Interests Adjustments to reconcile net income (loss) to net cash used in operating activities of Consolidated Funds: Adjustments To Reconcile Net Income (Loss) To Net Cash Provided By Operating Activities Of Consolidated Funds [Abstract] Adjustments To Reconcile Net Income (Loss) To Net Cash Provided By Operating Activities Of Consolidated Funds Document Quarterly Report Document Quarterly Report Total assets Assets, Fair Value Disclosure Related party, beneficial owner, minimum percentage Related Party, Beneficial Owner, Minimum Percentage Related Party, Beneficial Owner, Minimum Percentage Change in deferred income taxes Deferred Income Taxes and Tax Credits Change in Unrecognized Tax Benefit, Reasonably Possible [Table] Change in Unrecognized Tax Benefit, Reasonably Possible [Table] Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Amounts payable to StepStone Funds Other Liabilities, StepStone Funds [Member] Other Liabilities, StepStone Funds Counterparty Name [Domain] Counterparty Name [Domain] FY2028 Lessee, Operating Lease, Liability, to be Paid, Year Two Number of operating segments Number of Operating Segments Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Exchange One Exchange One [Member] Exchange One Sterling Overnight Index Average Sterling Overnight Index Average [Member] Sterling Overnight Index Average Schedule of Debt Obligations Schedule of Debt [Table Text Block] Settlement of non-controlling interests related to awards of carried interest allocations Settlement of non-controlling interests related to awards of carried interest allocations Noncontrolling Interest, Increase From Settlement Of Non-Controlling Interests Related To Awards Of Carried Interest Allocations Noncontrolling Interest, Increase From Settlement Of Non-Controlling Interests Related To Awards Of Carried Interest Allocations Investment Type [Axis] Investment Type [Axis] Granted (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Related Party [Axis] Related and Nonrelated Parties [Axis] Investments, at fair value Investments Title Trading Arrangement, Individual Title Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Schedule of Intangible Assets, Net Schedule of Finite-Lived Intangible Assets [Table Text Block] Incentive fees Total incentive fees Incentive Fees [Member] Incentive Fees Restatement Determination Date: Restatement Determination Date [Axis] Non-PEO NEO Non-PEO NEO [Member] Letters of credit outstanding Letters of Credit Outstanding, Amount Contributions Noncontrolling Interest, Increase from Subsidiary Equity Issuance Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Other financing activities Proceeds from (Payment for) Other Financing Activity Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Schedule of Fair Value of Liabilities and Assets Fair Value, Liabilities Measured on Recurring Basis [Table Text Block] Sale of Stock [Axis] Sale of Stock [Axis] GBP Base Rate GBP Base Rate [Member] GBP Base Rate Name Trading Arrangement, Individual Name Award Type [Domain] Award Type [Domain] FY2027 Lessee, Operating Lease, Liability, to be Paid, Year One Class D exchange agreement, period Transaction Agreement, Maximum Period To Exchange Shares Transaction Agreement, Maximum Period To Exchange Shares Incremental income from assumed shares Dilutive Securities, Effect on Basic Earnings Per Share, Options and Restrictive Stock Units Non-controlling interests Less: Amounts attributable to non-controlling interests Equity, Attributable to Noncontrolling Interest Equity Awards Adjustments Equity Awards Adjustments [Member] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Purchase of non-controlling interests Redemption of redeemable non-controlling interests Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests Investments in funds Equity Method Investments, Excluding Accrued Carried Interest Allocations Equity Method Investments, Excluding Accrued Carried Interest Allocations Compensation Amount Outstanding Recovery Compensation Amount Senior notes issued Debt Instrument, Face Amount Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Statement of Comprehensive Income [Abstract] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Deferred revenue, revenue recognized Contract with Customer, Liability, Revenue Recognized Accrued compensation and benefits Increase (Decrease) in Employee Related Liabilities MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Name Awards Close in Time to MNPI Disclosures, Individual Name Fund Credit Facility Fund Credit Facility [Member] Fund Credit Facility Beginning balance (in dollars per share) Ending balance (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Fair value adjustment for acquisition-related contingent consideration Business Combination, Contingent Consideration, Change in Contingent Consideration, Liability, Increase (Decrease) Weighted-average shares of Class A common stock: Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Employee Stock Employee Stock [Member] Investment in fund, before eliminations Investment In Fund, Before Eliminations Investment In Fund, Before Eliminations Revenues Revenues [Abstract] Exchange of Class B, Class C and Class D units for Class A common stock and redemption of corresponding Class B common stock Stock Issued During Period, Value, Conversion of Convertible Securities Maximum share purchase (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Maximum Number of Shares Per Employee Equity-based compensation APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Consolidated Entity, Excluding Consolidated VIE Consolidated Entity, Excluding Consolidated VIE [Member] Base interest rate Debt Instrument, Base Interest Rate Debt Instrument, Base Interest Rate Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Percentage of total net cash savings due to exchanging limited partners Incremental Net Cash Tax Savings Due To Exchanging Limited Partners, Percent Incremental Net Cash Tax Savings Due To Exchanging Limited Partners, Percent Minimum Minimum [Member] Trading multiple Liability Classified Award, Trading Multiple Liability Classified Award, Trading Multiple Non-Controlling Interests Consolidation, Subsidiaries or Other Investments, Consolidated Entities, Policy [Policy Text Block] Company Selected Measure Name Company Selected Measure Name Fund reimbursement revenues Management And Advisory Fees, Net, Fund Reimbursement Revenues [Member] Management And Advisory Fees, Net, Fund Reimbursement Revenues Revenues Revenue [Policy Text Block] Senior Notes Senior Notes [Member] Debt Obligations Debt Disclosure [Text Block] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Operating cash flows used for operating leases Operating Lease, Payments Membership ownership percentage Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Total performance fee-related compensation Performance Fee-Related Compensation Related to Carried Interest Allocation Performance Fee-Related Compensation Related to Carried Interest Allocation Net income (loss) attributable to StepStone Group Inc. – Diluted Net Income (Loss) Available to Common Stockholders, Diluted All Executive Categories All Executive Categories [Member] Common stock Common Stock, Value, Issued Legacy Greenspring accrued carried interest allocations Legacy Accrued Carried Interest Allocations Legacy Accrued Carried Interest Allocations Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Diluted (in shares) Weighted-average shares of Class A common stock outstanding - Diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Accrued carried interest allocations Equity Method Investments, Accrued Carried Interest Allocations Equity Method Investments, Accrued Carried Interest Allocations Total equity method income Revenue Not From Contract With Customer, Income Loss From Equity Method Investments And Investment Income Revenue Not From Contract With Customer, Income Loss From Equity Method Investments And Investment Income Segments Segment Reporting, Policy [Policy Text Block] Commitments and contingencies (Note 14) Commitments and Contingencies Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Performance fee-related compensation: Share-Based Payment Arrangement, Recognized Amount [Abstract] Fair Value Measured at Net Asset Value Per Share Fair Value Measured at Net Asset Value Per Share [Member] Business Combination [Axis] Business Combination [Axis] Comprehensive income (loss) before non-controlling interests Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Proceeds from sale of investments of Consolidated Funds Proceeds From Sale Of Consolidated Funds Proceeds From Sale Of Consolidated Funds Entity Small Business Entity Small Business Accounting Standards Update and Change in Accounting Principle [Table] Accounting Standards Update and Change in Accounting Principle [Table] Revenue from External Customers by Geographic Areas Revenue from External Customers by Geographic Areas [Table Text Block] Income Tax Disclosure [Abstract] Less: Net income attributable to redeemable non-controlling interests in Consolidated Funds Net income Net Income (Loss) Attributable to Redeemable Noncontrolling Interest Noncontrolling Interest Noncontrolling Interest [Member] Preferred stock, shares outstanding (in shares) Preferred Stock, Shares Outstanding Accrued carried interest-related compensation Equity Method Investment, Accrued Carried Interest Related Compensation Payable Equity Method Investment, Accrued Carried Interest Related Compensation Payable Document Transition Report Document Transition Report Underlying Securities Award Underlying Securities Amount Equity Component [Domain] Equity Component [Domain] Statement of Partners' Capital [Abstract] Document Period End Date Document Period End Date PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Redemption of redeemable non-controlling interests Temporary Equity, Accretion to Redemption Value Equity reallocation between controlling and non-controlling interests Adjustments To Additional Paid In Capital, Reallocation Of Noncontrolling Interest Adjustments To Additional Paid In Capital, Reallocation Of Noncontrolling Interest Income Taxes Income Tax Disclosure [Text Block] Limited Partners Limited Partners [Member] Limited Partners Class A Common Stock Common Class A [Member] Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Revenue from Contract with Customer [Abstract] Legacy Greenspring investments in funds and accrued carried interest allocations Legacy Investments In Funds And Accrued Carried Interest Allocations Legacy Investments In Funds And Accrued Carried Interest Allocations Total stockholders’ equity Total stockholders' equity, beginning balance Total stockholders' equity, ending balance Total stockholders' equity Equity, Including Portion Attributable to Noncontrolling Interest Legacy gross carried interest allocation, focused comingled funds Legacy Gross Carried Interest Allocation, Focused Commingled Funds [Member] Legacy Gross Carried Interest Allocation, Focused Commingled Funds Document Type Document Type Fair Value, Inputs, Level 3 Level III Fair Value, Inputs, Level 3 [Member] Earnings Per Share Earnings Per Share [Text Block] Name Outstanding Recovery, Individual Name Additional paid-in capital Additional Paid in Capital Product and Service [Axis] Product and Service [Axis] Variable lease cost Variable Lease, Cost Revenues Revenue from contracts with customer Revenue from Contract with Customer, Excluding Assessed Tax Changes in assets fair value hierarchy levels Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net Exchange of Partnership Units for Common Stock Exchange Of Partnership Units For Common Stock [Member] Exchange Of Partnership Units For Common Stock All Individuals All Individuals [Member] Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Fair Value Disclosures [Abstract] Purchases of property and equipment Payments to Acquire Property, Plant, and Equipment Name Forgone Recovery, Individual Name Statistical Measurement [Axis] Statistical Measurement [Axis] Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Reconciliation of cash, cash equivalents and restricted cash: Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation [Abstract] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Discount rate Share-Based Compensation Arrangement by Share-Based Payment Award, Purchase Price of Common Stock, Percent Deferred tax effect resulting from transactions affecting ownership in the Partnership, including net amounts payable under Tax Receivable Agreements Deferred Tax Effect From Purchase Of Units, Net Deferred Tax Effect From Purchase Of Units, Net Equity Method Investee Equity Method Investee [Member] Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Entity Information [Line Items] Entity Information [Line Items] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Schedule of Finite-Lived Intangible Assets [Table] Intangible Asset, Finite-Lived [Table] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Geographical [Axis] Geographical [Axis] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Level I Fair Value, Inputs, Level 1 [Member] Partner Type of Partners' Capital Account, Name [Domain] Partner Type of Partners' Capital Account, Name [Domain] Economic interest Economic Ownership Interest Economic Ownership Interest Schedule of Related Party Transactions, by Related Party [Table] Related Party Transaction [Table] Diluted (in dollars per share) Diluted (in dollars per share) Earnings Per Share, Diluted Consolidated Entities, Excluding Legacy Entities Consolidated Entities, Excluding Legacy Entities [Member] Consolidated Entities, Excluding Legacy Entities Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Title of 12(b) Security Title of 12(b) Security Tax Receivable Agreements Tax Receivable Agreement, Policy [Policy Text Block] Tax Receivable Agreement, Policy Other comprehensive income (loss): Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Dividends [Axis] Dividends [Axis] Net income (loss) per share of Class A common stock: Earnings Per Share [Abstract] Total other income Nonoperating Income (Expense) Noncontrolling interest, ownership by parent Subsidiary, Ownership Percentage, Parent Distributions received from investments Proceeds from Equity Method Investment, Distribution, Return of Capital Variable Interest Entity, Not Primary Beneficiary Variable Interest Entity, Not Primary Beneficiary [Member] Cash flows from financing activities of Consolidated Funds: Adjustments To Reconcile Net Income (Loss) To Cash Provided By (Used In) Financing Activities [Abstract] Adjustments To Reconcile Net Income (Loss) To Cash Provided By (Used In) Financing Activities, Consolidated Funds Investments Equity Method Investments and Joint Ventures Disclosure [Text Block] Focused commingled funds Incentive Fees, Focused Commingled Funds [Member] Incentive Fees, Focused Commingled Funds Consolidated Funds Consolidated Funds [Member] Consolidated Funds Accumulated Other Comprehensive Income Comprehensive Income, Policy [Policy Text Block] Class A common stock issued for purchase of asset class non-controlling interests Stock Issued During Period, Value, Purchase Of Asset Class Non-Controlling Interests Stock Issued During Period, Value, Purchase Of Asset Class Non-Controlling Interests Less: Imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Carried interest allocations Carried Interest Allocation [Member] Carried Interest Allocation Class A common stock issued in exchange for Class B, Class C and Class D partnership units (in shares) Stockholders' Equity, Units Exchanged In Offering, Shares Stockholders' Equity, Units Exchanged In Offering, Shares Three Investments Three Investments [Member] Three Investments Series A 5.52% Notes Series A 5.52% Notes [Member] Series A 5.52% Notes Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Payments to related parties under Tax Receivable Agreements Payments to related parties under Tax Receivable Agreements Payments To Related Parties, Tax Receivable Agreements Payments To Related Parties, Tax Receivable Agreements FY2028 Finite-Lived Intangible Asset, Expected Amortization, Year Two Award Timing Disclosures [Line Items] Total remaining principal Long-Term Debt, Gross Measurement Frequency [Domain] Measurement Frequency [Domain] Total lease liabilities Lessee, Operating Lease, Liability, to be Paid Non-Controlling Interests in Subsidiaries Subsidiaries [Member] Partner Type [Axis] Partner Type [Axis] Stockholders' Equity and Redeemable Non-Controlling Interests Equity [Text Block] Purchase period Share-Based Compensation Arrangement By Share-based Payment Award, Purchase Period Share-Based Compensation Arrangement By Share-based Payment Award, Purchase Period Distributions Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Accounting for Differing Fiscal Periods Fiscal Period, Policy [Policy Text Block] Net income (loss) attributable to StepStone Group Inc. Net income (loss) attributable to StepStone Group Inc. – Basic Net Income (Loss) Attributable to Parent Subsequent Event [Table] Subsequent Event [Table] Dividends [Domain] Dividends [Domain] Expiration Date Trading Arrangement Expiration Date Other liabilities and payables Increase (Decrease) in Other Operating Liabilities Product Information [Line Items] Product Information [Line Items] Stockholders’ equity: Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Schedule of Equity Method Investments Equity Method Investments [Table Text Block] Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Total carried interest allocations Revenue Not from Contract with Customer Adoption Date Trading Arrangement Adoption Date Comingled Funds Concentration Risk Comingled Funds Concentration Risk [Member] Comingled Funds Concentration Risk Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Fees and accounts receivable Increase (Decrease) in Accounts Receivable Entity Current Reporting Status Entity Current Reporting Status Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Client relationships Customer Relationships [Member] Credit Agreement Line of Credit [Member] Consolidated Entities [Domain] Consolidated Entities [Domain] Liability classified awards, settlement Share-Based Payment Arrangement, Cash Used to Settle Award Compensation and Benefits Compensation Related Costs, Policy [Policy Text Block] Accumulated deficit Retained Earnings (Accumulated Deficit) Deferred tax effect resulting from transactions affecting ownership in the Partnership Adjustments To Additional Paid In Capital, Deferred Tax Effect Of Exchange Adjustments To Additional Paid In Capital, Deferred Tax Effect Of Exchange Liability classified awards recognized in accounts payable, accrued expenses, and other liabilities Deferred Compensation Share-Based Arrangements, Liability, Current and Noncurrent Adjustments to reconcile net income (loss) to net cash provided by operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Noncash Item [Abstract] Statement of Financial Position [Abstract] Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Executive Category: Executive Category [Axis] Current Fiscal Year End Date Current Fiscal Year End Date Class of Stock [Axis] Class of Stock [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Due to affiliates Increase (Decrease) in Due to Related Parties Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Impairment of finite-lived intangible assets Impairment of Intangible Assets, Finite-Lived Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Weighted-Average Grant-Date Fair Value Per RSU and PRSU Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Other income (loss) Other Nonoperating Income (Expense) Statement [Table] Statement [Table] Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Earnings Per Share, Basic, by Common Class, Including Two-Class Method [Table] Cash flows from financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Partnerships and LLC Interests Partnerships and LLC Interests [Member] Partnerships and LLC Interests Revenue Benchmark Revenue Benchmark [Member] Variable Rate [Domain] Variable Rate [Domain] Deferred revenue Contract with Customer, Liability Organization Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Unrecognized tax benefits Unrecognized Tax Benefits Spread on base commitment fee percentage if utilization less than 50% Line Of Credit Facility, Commitment Fee Percentage, Spread On Base If Utilization Less Than 50 Percent Line Of Credit Facility, Commitment Fee Percentage, Spread On Base If Utilization Less Than 50 Percent Antidilutive securities excluded from computation of earnings per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Denominator: Weighted Average Number of Shares Outstanding, Diluted [Abstract] All Adjustments to Compensation All Adjustments to Compensation [Member] Class B2 units Class B2 Unit [Member] Class B2 Unit Amendment Flag Amendment Flag Lease right-of-use assets, net and lease liabilities Increase (Decrease) In Lease Right Of Use Assets, Net Of Lease Liabilities Increase (Decrease) In Lease Right Of Use Assets, Net Of Lease Liabilities Legacy Greenspring accrued carried interest-related compensation Legacy Investment, Accrued Carried Interest Related Compensation Payable Legacy Investment, Accrued Carried Interest Related Compensation Payable Other Commitments [Table] Other Commitments [Table] Termination Date Trading Arrangement Termination Date Net cash used in financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Measure: Measure [Axis] Weighted-average discount rate for operating leases Operating Lease, Weighted Average Discount Rate, Percent Variable Interest Entity, Not Primary Beneficiary, Legacy Entities Variable Interest Entity, Not Primary Beneficiary, Legacy Entities [Member] Variable Interest Entity, Not Primary Beneficiary, Legacy Entities Annual exchanges Transaction Agreement, Number of Annual Exchanges Transaction Agreement, Number of Annual Exchanges Due from affiliates Increase (Decrease) in Due from Related Parties Basic (in shares) Weighted-average shares of Class A common stock outstanding – Basic (in shares) Weighted Average Number of Shares Outstanding, Basic Transaction agreement, exchange ratio Transaction Agreement, Exchange Ratio Transaction Agreement, Exchange Ratio Eurodollar Eurodollar [Member] 1 Month Term Secured Overnight Financing Rate (SOFR) 1 Month Term Secured Overnight Financing Rate (SOFR) [Member] 1 Month Term Secured Overnight Financing Rate (SOFR) Schedule of Reconciliations of Basic and Diluted Earnings Per Share of Class A Common Stock Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of Investments of Consolidated Funds Consolidated Funds Investments [Table Text Block] Consolidated Funds Investments Related Party Transaction [Domain] Related Party Transaction [Domain] Subsequent Events [Abstract] Segment Reporting [Abstract] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Performance-Based Restricted Stock Units Performance-Based Restricted Stock Units [Member] Performance-Based Restricted Stock Units Common stock, number of votes Common Stock, Number of Votes Common Stock, Number of Votes Debt Disclosure [Abstract] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Other income (expense) Nonoperating Income (Expense) [Abstract] Entity Tax Identification Number Entity Tax Identification Number Expenses Costs and Expenses [Abstract] Schedule of Carrying Value of the Assets and Liabilities of the Company's Variable Interest Entities Schedule of Variable Interest Entities [Table Text Block] Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Carried interest allocation as percentage of cumulative fund or account performance Revenue, Carried Interest Allocation As Percentage Of Cumulative Fund Or Account Performance Revenue, Carried Interest Allocation As Percentage Of Cumulative Fund Or Account Performance Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Consolidated Entities [Axis] Consolidated Entities [Axis] Class Of Partnership Unit [Domain] Class Of Partnership Unit [Domain] Class Of Partnership Unit [Domain] Common stock, shares issued (in shares) Common Stock, Shares, Issued Weighted-average remaining lease term for operating leases Operating Lease, Weighted Average Remaining Lease Term Summary of Noncontrolling Interests In Consolidated Funds Redeemable Noncontrolling Interest [Table Text Block] SPD SPD [Member] SPD Intangibles and Goodwill Goodwill and Intangible Assets Disclosure [Text Block] Increase in due to related parties, tax receivable agreements Increase (Decrease) In Due To Related Parties, Tax Receivable Agreements Increase (Decrease) In Due To Related Parties, Tax Receivable Agreements Accrued dividends Dividends Payable, Current Interest expense Interest Expense, Nonoperating Trading Arrangement: Trading Arrangement [Axis] Total Shareholder Return Amount Total Shareholder Return Amount Exchange Three Exchange Three [Member] Exchange Three Subsequent Events Subsequent Events [Text Block] Foreign currency translation adjustment Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Insider Trading Arrangements [Line Items] Security Exchange Name Security Exchange Name Payments to acquire additional interests Payments to Acquire Additional Interest in Subsidiaries Equity securities Equity Securities [Member] Total liabilities Liabilities Liabilities Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Distributions to non-controlling interests Payments of Ordinary Dividends, Noncontrolling Interest Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Performance Restricted Stock Units Performance Restricted Stock Units [Member] Performance Restricted Stock Units Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Current Events Current Events [Policy Text Block] Current Events Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Asset Class [Domain] Asset Class [Domain] Change in fair value Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Increase in deferred tax assets, exchange of partnership units for common stock Increase (Decrease) In Deferred Tax Assets, Exchange Of Partnership Units For Common Stock Increase (Decrease) In Deferred Tax Assets, Exchange Of Partnership Units For Common Stock Statement [Line Items] Statement [Line Items] Variable Rate [Axis] Variable Rate [Axis] Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Cash and cash equivalents Cash and Cash Equivalent Counterparty Name [Axis] Counterparty Name [Axis] Subsequent Event [Line Items] Subsequent Event [Line Items] Spread on base commitment fee percentage if utilization greater than 50% Line Of Credit Facility, Commitment Fee Percentage, Spread On Base If Utilization Greater Than 50 Percent Line Of Credit Facility, Commitment Fee Percentage, Spread On Base If Utilization Greater Than 50 Percent Common Stock Common Stock [Member] Vested (in shares) Vested (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period Cash-based compensation, term Deferred Compensation Arrangement with Individual, Maximum Contractual Term Net income (loss) Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest Accrued compensation and benefits Employee-related Liabilities Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Non-NEOs Non-NEOs [Member] Subsidiary, Sale of Stock [Line Items] Subsidiary, Sale of Stock [Line Items] Net increase (decrease) in cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Equity issued for redemption of redeemable non-controlling interests Stock Issued For Acquisitions Stock Issued For Acquisitions