Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Document Type Document Type Other income (loss) Other Nonoperating Income (Expense) Income from equity method investments Income (Loss) from Equity Method Investments, Including Revenue Not From Contract With Customer Income (Loss) from Equity Method Investments, Including Revenue Not From Contract With Customer Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Related Party [Axis] Related Party [Axis] Schedule of Carrying Value of the Assets and Liabilities of the Company's Variable Interest Entities Schedule of Variable Interest Entities [Table Text Block] Product Information [Line Items] Product Information [Line Items] 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 Schedule of Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Level III Fair Value, Inputs, Level 3 [Member] Proceeds from sales and maturities of marketable securities Proceeds from Sale and Maturity of Marketable Securities Total compensation and benefits Compensation And Benefits Expense Compensation And Benefits Expense Partners’ Capital Limited Partner [Member] Statistical Measurement [Domain] Statistical Measurement [Domain] Liabilities and stockholders’ equity / partners’ capital Liabilities and Equity [Abstract] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Distributions Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Security Exchange Name Security Exchange Name Unrealized Performance Fee-Related Compensation Related to Carried Interest Allocation, Unrealized Performance Fee-Related Compensation Related to Carried Interest Allocation, Unrealized Intangibles, net Intangible Assets, Net (Excluding Goodwill) Contributed capital Partners' Capital Account, Contributions Thereafter Finite-Lived Intangible Asset, Expected Amortization, after Year Four Finite-Lived Intangible Asset, Expected Amortization, after Year Four 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 Commitments and contingencies (Note 14) Commitments and Contingencies Number of classes of common stock outstanding Number Of Classes Of Common Stock Outstanding Number Of Classes Of Common Stock Outstanding Assets Assets [Abstract] Investment, Name [Axis] Investment, Name [Axis] Vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Accounting Policies [Abstract] Subsidiaries Subsidiaries [Member] Restricted Cash Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Entity Address, State or Province Entity Address, State or Province Vested (in shares) Vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Number of shares owned after all transactions (in shares) Number Of Shares Owned After All Transactions Number Of Shares Owned After All Transactions Net income per share of Class A common stock: Earnings Per Share Reconciliation [Abstract] Retained earnings Retained Earnings (Accumulated Deficit) Certain employee equity holders Investor [Member] Number of cities for leased offices Lessee, Operating Lease, Number Of Cities Lessee, Operating Lease, Number Of Cities Reconciliation of cash, cash equivalents and restricted cash: Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract] Class B Common Stock Common Class B [Member] Unrecognized non-cash compensation Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Income Taxes Income Tax, Policy [Policy Text Block] Contributions to investments Payments to Acquire Equity Method Investments Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share SMAs Carried Interest Allocation, Separately Managed Accounts [Member] Carried Interest Allocation, Separately Managed Accounts Other comprehensive income: Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Deferred income tax assets Deferred Income Tax Assets, Net Non-controlling interests in subsidiaries Partners' Capital Attributable to Noncontrolling Interest Equity-based compensation APIC, Share-based Payment Arrangement, Increase for Cost Recognition Revenue, carried interest allocation, minimum return levels required Revenue, Carried Interest Allocation, Minimum Return Levels Required Revenue, Carried Interest Allocation, Minimum Return Levels Required Effect of foreign currency exchange rate changes Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Service fees Revenues Revenue from Contract with Customer, Excluding Assessed Tax Measurement Frequency [Domain] Measurement Frequency [Domain] Investments Investment, Policy [Policy Text Block] Purchase of non-controlling partnership interests payable Liabilities Assumed Equity method investment, total accrued carried interest allocation percentage Concentration Risk, Percentage Geographical [Domain] Geographical [Domain] Dividends payable (in dollars per share) Dividends Payable, Amount Per Share Advisory and other services Management And Advisory Fees, Net, Advisory And Other Services [Member] Management And Advisory Fees, Net, Advisory And Other Services Statement [Line Items] Statement [Line Items] Class of Stock [Domain] Class of Stock [Domain] Partnership Partnership Of Subsidiary [Member] Partnership Of Subsidiary Measurement Input Type [Domain] Measurement Input Type [Domain] Statement [Table] Statement [Table] Statistical Measurement [Axis] Statistical Measurement [Axis] Realized allocation Carried Interest Allocation, Realized [Member] Carried Interest Allocation, Realized Change in deferred income taxes Deferred Income Taxes and Tax Credits Realized Performance Fee-Related Compensation Related to Carried Interest Allocation, Realized Performance Fee-Related Compensation Related to Carried Interest Allocation, Realized 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 Infrastructure Subsidiary Infrastructure Subsidiary [Member] Infrastructure Subsidiary Entity Small Business Entity Small Business Consolidation Consolidation, Policy [Policy Text Block] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Shares sold in offering (in shares) Sale of Stock, Number of Shares Issued in Transaction Debt Obligations Debt Disclosure [Text Block] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] SMAs Management And Advisory Fees, Net, Separately Managed Accounts [Member] Management And Advisory Fees, Net, Separately Managed Accounts Amendment Flag Amendment Flag 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] Total Operating Leases, Future Minimum Payments Due Remainder of FY2021 Operating Leases, Future Minimum Payments, Remainder of Fiscal Year Denominator: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Management and advisory fees, net Management And Advisory Fees, Net [Member] Management And Advisory Fees, Net Balance, beginning of period: Balance, end of period: Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value Deferred tax effect resulting from purchase of Class B units, net of amounts payable under TRA Adjustments To Additional Paid In Capital, Deferred Tax Effect Adjustments To Additional Paid In Capital, Deferred Tax Effect Number of shares available for grant (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Fair Value Measurements Fair Value Measurement, Policy [Policy Text Block] Schedule of Equity Method Investments Equity Method Investments [Table Text Block] Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Distributions to non-controlling interests Payments of Ordinary Dividends, Noncontrolling Interest Entity Central Index Key Entity Central Index Key Related Party [Domain] Related Party [Domain] Measurement Frequency [Axis] Measurement Frequency [Axis] Schedule of Common Stock Outstanding [Roll Forward] Schedule of Common Stock Outstanding [Roll Forward] Schedule of Common Stock Outstanding Related Party Transaction [Line Items] Related Party Transaction [Line Items] Carried interest allocation revenues Carried Interest Allocation Revenues [Member] Carried Interest Allocation Revenues Unrealized carried interest allocation and investment income Carried Interest Allocation And Investment Income, Unrealized Gain (Loss) Carried Interest Allocation And Investment Income, Unrealized Gain (Loss) Maximum exposure to loss Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount Schedule of Intangible Assets, Net Schedule of Finite-Lived Intangible Assets [Table Text Block] Due from affiliates Due from Related Parties Accounts payable, accrued expenses and other liabilities Accounts Payable and Other Accrued Liabilities Statement of Partners' Capital [Abstract] Geographical [Axis] Geographical [Axis] Subsequent Events Subsequent Events [Text Block] Statement of Cash Flows [Abstract] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Due from affiliates Increase (Decrease) in Due from Related Parties Due to related parties, tax receivable agreements Due To Related Parties, Tax Receivable Agreements Due To Related Parties, Tax Receivable Agreements Cash flows from financing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Amortization of intangible assets Amortization of Intangible Assets Plan Name [Axis] Plan Name [Axis] Investments Equity Method Investments and Joint Ventures Disclosure [Text Block] Sale of partnership interests Partners' Capital Account, Sale of Units Issuance of Class A common stock sold in IPO, net of underwriting discounts Stock Issued During Period, Value, New Issues Stock Conversion Description [Axis] Stock Conversion Description [Axis] Total assets Assets Assets Related Party Transactions Related Party Transactions Disclosure [Text Block] Unvested (in shares) RSUs, beginning balance (in shares) RSUs, ending balance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Title of 12(b) Security Title of 12(b) Security Intangibles, net Finite-Lived Intangible Assets, Net Subsequent Event Type [Axis] Subsequent Event Type [Axis] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Interest expense Interest Expense Net proceeds from stock offering Sale of Stock, Consideration Received on Transaction Depreciation and amortization Depreciation, Depletion and Amortization Total carried interest allocation Revenue Not from Contract with Customer Product and Service [Axis] Product and Service [Axis] Total liabilities Liabilities Liabilities Partner Capital Components [Axis] Partner Capital Components [Axis] Unrecognized non-cash compensation, period of recognition Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Carried interest allocation: Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract] Non-U.S. countries Non-US [Member] Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Schedule of Rollforward of the Company's Shares of Common Stock Outstanding Since IPO Schedule of Stock by Class [Table Text Block] Deferred revenue, revenue recognized Contract with Customer, Liability, Revenue Recognized Commitments and Contingencies Disclosure [Abstract] Level I Fair Value, Inputs, Level 1 [Member] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Unrealized allocation Carried Interest Allocation, Unrealized [Member] Carried Interest Allocation, Unrealized Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Number of RSUs Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Shares redeemed (in shares) Stock Redeemed or Called During Period, Shares Sale of non-controlling interests prior to Reorganization and IPO Noncontrolling Interest, Increase from Sale of Parent Equity Interest Additional Paid-in Capital Additional Paid-in Capital [Member] Partner Type [Axis] Partner Type [Axis] Other assets and receivables Other Assets Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Total StepStone Group Inc. partners' capital Partners' Capital Revenue from Contract with Customer [Abstract] Sublease, payments to be received Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals Granted shares, fair value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Granted in Period, Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Granted in Period, Fair Value Investments in funds Equity Method Investments 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 Entity Information [Line Items] Entity Information [Line Items] Income Tax Disclosure [Abstract] Cash-based compensation Compensation Expense, Cash Based Compensation And Benefits Compensation Expense, Cash Based Compensation And Benefits Variable Interest Entities Variable Interest Entity Disclosure [Text Block] Income before income tax Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Adjustments to reconcile net income to net cash provided by operating activities: Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] IPO IPO [Member] Variable Interest Entity, Not Primary Beneficiary Variable Interest Entity, Not Primary Beneficiary [Member] Subsequent Event Subsequent Event [Member] Equity reallocation between controlling and non-controlling interests prior to Reorganization and IPO Partners' Capital Account, Reallocation Between Controlling And Non-Controlling Interest Partners' Capital Account, Reallocation Between Controlling And Non-Controlling Interest Accumulated Other Comprehensive Income Comprehensive Income, Policy [Policy Text Block] Reclassifications Reclassification, Comparability Adjustment [Policy Text Block] Common stock, shares authorized (in shares) Common Stock, Shares Authorized Concentration Risk Type [Axis] Concentration Risk Type [Axis] Assumed vesting and exchange of restricted share units and Class B units (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Revenue from External Customers by Geographic Areas Revenue from External Customers by Geographic Areas [Table Text Block] Purchase of non-controlling interests prior to Reorganization and IPO Purchase of partnership interests Partners' Capital Account, Treasury Units, Purchased Conversion of Class B Partnership Units to Class A Common Stock Conversion of Class B Partnership Units to Class A Common Stock [Member] Conversion of Class B Partnership Units to Class A Common Stock 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] Partners’ capital Limited Partners' Capital Account Focused commingled funds Carried Interest Allocation, Focused Commingled Funds [Member] Carried Interest Allocation, Focused Commingled Funds Revenues Revenue [Policy Text Block] 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 Incremental income from assumed vesting and exchange of restricted share units and Class B units Dilutive Securities, Effect on Basic Earnings Per Share, Options and Restrictive Stock Units Partnership StepStone Group LP [Member] StepStone Group LP Due to affiliates Increase (Decrease) in Due to Related Parties Accrued compensation and benefits Increase (Decrease) in Employee Related Liabilities Income Statement [Abstract] Accumulated Other Comprehensive Income (Loss) Accumulated other comprehensive income AOCI Attributable to Parent [Member] FY2025 Finite-Lived Intangible Asset, Expected Amortization, Year Four Operating leases, rent expense Operating Leases, Rent Expense Variable Interest Entity, Primary Beneficiary Variable Interest Entity, Primary Beneficiary [Member] Additions Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases Changes to uncertain tax positions Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit LTIP 2020 Long-Term Incentive Plan [Member] 2020 Long-Term Incentive Plan Interest income Investment Income, Interest Proceeds from capital contributions from non-controlling interests Proceeds from Partnership Contribution Consolidated Entities [Axis] Consolidated Entities [Axis] Comprehensive income attributable to StepStone Group Inc. Comprehensive Income (Loss), Net of Tax, Attributable to Parent Effect of Reorganization and purchase of units in the Partnership Stockholders' Equity, Effect Of Reorganization Stockholders' Equity, Effect Of Reorganization Separately Managed Account Concentration Risk Separately Managed Account Concentration Risk [Member] Separately Managed Account Concentration Risk Legal Entity [Axis] Legal Entity [Axis] Purchases of property and equipment Payments to Acquire Property, Plant, and Equipment City Area Code City Area Code Document Period End Date Document Period End Date Contingent consideration obligation Business Combination, Contingent Consideration, Liability Intangibles and Goodwill Goodwill and Intangible Assets Disclosure [Text Block] Focused commingled funds Management And Advisory Fees, Net, Focused Commingled Funds [Member] Management And Advisory Fees, Net, Focused Commingled Funds Distributions prior to Reorganization and IPO Distributions Partners' Capital Account, Distributions Investment income Income (Loss) from Equity Method Investments Net income Net income Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Schedule of Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Equity reallocation between controlling and non-controlling interests subsequent to Reorganization and IPO Stockholders' Equity, Reallocation Between Controlling And Non-Controlling Interest Stockholders' Equity, Reallocation Between Controlling And Non-Controlling Interest Accrued compensation and benefits Employee-related Liabilities Goodwill, impairment loss Goodwill, Impaired, Accumulated Impairment Loss Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Equity-based compensation Share-based Payment Arrangement, Noncash Expense Entity [Domain] Entity [Domain] Other financing activities Proceeds from (Payments for) Other Financing Activities Cover [Abstract] Measurement Input Type [Axis] Measurement Input Type [Axis] SMAs Incentive Fees, Separately Managed Accounts [Member] Incentive Fees, Separately Managed Accounts StepStone Funds Equity Method Investee [Member] Non-controlling interest holders Affiliated Entity [Member] Debt obligations Long-term Debt Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Fair Value Disclosures [Abstract] Ownership percentage Cumulative Percentage Ownership after All Transactions Cumulative Percentage Ownership after All Transactions Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Total expenses Costs and Expenses Equity Components [Axis] Equity Components [Axis] Partner Capital Components [Domain] Partner Capital Components [Domain] Share-based Payment Arrangement [Abstract] Minimum Minimum [Member] Incentive fees Total incentive fees Incentive Fees [Member] Incentive Fees Consolidated Entities [Domain] Consolidated Entities [Domain] Less: Net income attributable to non-controlling interests Net Income (Loss) Attributable to Noncontrolling Interest Equity Method Investments and Joint Ventures [Abstract] Schedule of Fair Value of Liabilities Fair Value, Liabilities Measured on Recurring Basis [Table Text Block] 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 Entity Interactive Data Current Entity Interactive Data Current United States UNITED STATES Increase (Decrease) in Partners' Capital [Roll Forward] Increase (Decrease) in Partners' Capital [Roll Forward] Revenues Revenues [Abstract] Fair Value Measurements Fair Value Disclosures [Text Block] Cash flows from operating activities Net Cash Provided by (Used in) Operating Activities [Abstract] Stockholders' Equity Stockholders' Equity Note Disclosure [Text Block] Remainder of FY2021 Finite-Lived Intangible Asset, Expected Amortization, Remainder of Fiscal Year Equity-Based Compensation Share-based Payment Arrangement [Policy Text Block] Investments in funds Equity Method Investments, Excluding Accrued Carried Interest Allocations Equity Method Investments, Excluding Accrued Carried Interest Allocations Accounting for Differing Fiscal Periods Fiscal Period, Policy [Policy Text Block] Entity Registrant Name Entity Registrant Name Subsequent Event Type [Domain] Subsequent Event Type [Domain] Issued to Class B unitholders in the Reorganization / Class A partnership units exchanged in the Reorganization (in shares) Stockholders' Equity, Effect Of Reorganization, Shares Stockholders' Equity, Effect Of Reorganization, Shares Number of reportable segments Number of Reportable Segments Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Investments: Investments [Abstract] Compensation and benefits: Income Statement Compensation Expense Items [Abstract] Equity-based compensation Partners' Capital Account, Unit-based Payment Arrangement, Amount Purchase of partnership interests with IPO net proceeds Adjustments To Additional Paid In Capital, Purchase Of Partnership Interests Adjustments To Additional Paid In Capital, Purchase Of Partnership Interests Sale of Stock [Axis] Sale of Stock [Axis] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Deferred tax assets, net of valuation allowance Deferred Tax Assets, Net of Valuation Allowance Goodwill Goodwill Fund reimbursement revenues Management And Advisory Fees, Net, Fund Reimbursement Revenues [Member] Management And Advisory Fees, Net, Fund Reimbursement Revenues Owners Owners [Member] Owners Document Transition Report Document Transition Report General Partner General Partner [Member] Other income (expense) Nonoperating Income (Expense) [Abstract] Total performance fee-related compensation Performance Fee-Related Compensation Related to Carried Interest Allocation Performance Fee-Related Compensation Related to Carried Interest Allocation Level II Fair Value, Inputs, Level 2 [Member] Document Quarterly Report Document Quarterly Report Business combination, contingent consideration, liability, measurement input Business Combination, Contingent Consideration, Liability, Measurement Input Equity [Abstract] Conversion of stock (in shares) Conversion of Stock, Shares Converted Accrued carried interest allocations Equity Method Investments, Accrued Carried Interest Allocations Equity Method Investments, Accrued Carried Interest Allocations Deferred IPO costs Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Two Investments Two Investments [Member] Two Investments Subsequent Event [Line Items] Subsequent Event [Line Items] Entities [Table] Entities [Table] Schedule of Future Amortization of Finite-lived Intangible Assets Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Diluted (in shares) Weighted-average shares of Class A common stock outstanding - Diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Basic (in dollars per share) Basic (in dollars per share) Earnings Per Share, Basic Accrued carried interest-related compensation Equity Method Investment, Accrued Carried Interest Related Compensation Payable Equity Method Investment, Accrued Carried Interest Related Compensation Payable Number of operating segments Number of Operating Segments Conversion of Stock, Name [Domain] Conversion of Stock, Name [Domain] Entity File Number Entity File Number Forfeited (in shares) Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Debt Disclosure [Abstract] Deferred tax asset, reorganization and initial public offering transactions Deferred Tax Asset, Reorganization And Initial Public Offering Transactions Deferred Tax Asset, Reorganization And Initial Public Offering Transactions Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities Principal payments on term loan Principal payments on term loan Repayments of Long-term Debt Sale of non-controlling interests Sale of partnership interests Proceeds from Noncontrolling Interests Conversion of Class B Units to Class B Common Stock Conversion of Class B Units to Class B Common Stock [Member] Conversion of Class B Units to Class B Common Stock Equity-based compensation Share-based Payment Arrangement, Expense Unrecognized tax benefits Unrecognized Tax Benefits Weighted-average shares of Class A common stock: Earnings Per Share, Basic and Diluted, Other Disclosures [Abstract] Common stock Common Stock, Value, Issued Accrued carried interest-related compensation Increase (Decrease) in Accrued Carried Interest-Related Compensation Payable Increase (Decrease) in Accrued Carried Interest-Related Compensation Payable Goodwill and Intangible Assets Disclosure [Abstract] Document Fiscal Year Focus Document Fiscal Year Focus FY2023 Finite-Lived Intangible Asset, Expected Amortization, Year Two Entity Current Reporting Status Entity Current Reporting Status Offering price per share (in dollars per share) Sale of Stock, Price Per Share (Gain) loss on change in fair value Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings Related Party Transaction [Axis] Related Party Transaction [Axis] Subsequent Event [Table] Subsequent Event [Table] Comprehensive income before non-controlling interests Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Non-controlling interests Less: Amounts attributable to non-controlling interests in subsidiaries Stockholders' Equity Attributable to Noncontrolling Interest 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 Cash flows from investing activities Net Cash Provided by (Used in) Investing Activities [Abstract] Common stock, shares issued (in shares) Common Stock, Shares, Issued Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Schedule of Product Information [Table] Schedule of Product Information [Table] Deferred tax effect resulting from purchase of Class B units, net of amounts payable under TRA Deferred Tax Effect From Purchase Of Units, Net Deferred Tax Effect From Purchase Of Units, Net Subsidiary or Equity Method Investee, Sale of Stock by Subsidiary or Equity Investee [Table] Subsidiary or Equity Method Investee, Sale of Stock by Subsidiary or Equity Investee [Table] Fees and accounts receivable Accounts Receivable, after Allowance for Credit Loss Fees and accounts receivable Increase (Decrease) in Accounts Receivable Partners’ Capital Partners' Capital [Member] Partners' Capital Statement of Comprehensive Income [Abstract] Total StepStone Group Inc. stockholders' equity Stockholders' Equity Attributable to Parent Payment of deferred offering costs Offering costs Payments of Stock Issuance Costs Concentration Risk Type [Domain] Concentration Risk Type [Domain] Total liabilities and stockholders' equity / partners' capital Liabilities and Equity Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax Income Taxes Income Tax Disclosure [Text Block] Entity Address, City or Town Entity Address, City or Town Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Restricted Stock Units (RSUs) Restricted Stock Units (RSUs) [Member] Blocker Entities Blocker Entities [Member] Blocker Entities General, administrative and other General and Administrative Expense FY2024 Operating Leases, Future Minimum Payments, Due in Four Years Antidilutive securities excluded from computation of earnings per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Total partners' capital Partners' capital, beginning balance Partners' capital, ending balance Total stockholders' equity / partners' capital Partners' Capital, Including Portion Attributable to Noncontrolling Interest Tax Receivable Agreements Tax Receivable Agreement, Policy [Policy Text Block] Tax Receivable Agreement, Policy Entity Ex Transition Period Entity Ex Transition Period Equity Component [Domain] Equity Component [Domain] Deferred tax assets, valuation allowance Deferred Tax Assets, Valuation Allowance FY2024 Finite-Lived Intangible Asset, Expected Amortization, Year Three Entity Tax Identification Number Entity Tax Identification Number Unrealized gains on marketable securities Marketable Securities, Unrealized Gain (Loss) Focused commingled funds Incentive Fees, Focused Commingled Funds [Member] Incentive Fees, Focused Commingled Funds Equity-Based Compensation Share-based Payment Arrangement [Text Block] Net income attributable to StepStone Group Inc. Net income attributable to StepStone Group Inc. – Basic Net Income (Loss) Attributable to Parent Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Schedule of Variable Interest Entities [Table] Schedule of Variable Interest Entities [Table] Purchase of non-controlling interests Purchase of non-controlling interests Payments to Noncontrolling Interests Investment, Name [Domain] Investment, Name [Domain] Total other comprehensive income Other comprehensive income Other Comprehensive Income (Loss), Net of Tax Performance fee-related compensation: Share-based Payment Arrangement, Expensed and Capitalized, Amount [Abstract] Current Fiscal Year End Date Current Fiscal Year End Date Three Investments Three Investments [Member] Three Investments Less: Comprehensive income attributable to non-controlling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Earnings per share of Class A common stock: Earnings Per Share [Abstract] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Unrealized loss on defined benefit plan, net Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Document Fiscal Period Focus Document Fiscal Period Focus Subsidiary, Sale of Stock [Line Items] Subsidiary, Sale of Stock [Line Items] Net income attributable to StepStone Group Inc. – Diluted Net Income (Loss) Available to Common Stockholders, Diluted Supplemental disclosures: Supplemental Cash Flow Information [Abstract] Membership ownership percentage Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest Entity Filer Category Entity Filer Category Common Stock Common Stock [Member] Foreign currency translation adjustments Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Product and Service [Domain] Product and Service [Domain] Unfunded capital commitments Off-Balance Sheet, Credit Loss, Liability Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Distributions received from investments Proceeds from Equity Method Investment, Distribution, Return of Capital Non-Controlling Interests Consolidation, Subsidiaries or Other Investments, Consolidated Entities, Policy [Policy Text Block] Due to affiliates Due to Related Parties Issued to public holders in the IPO (in shares) Stock Issued During Period, Shares, New Issues Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Management contracts Finite-Lived Intangible Assets, Gross Revenue Benchmark Revenue Benchmark [Member] Write-off of deferred debt issuance costs Write-off / amortization of deferred financing costs Write off of Deferred Debt Issuance Cost Class A Common Stock Common Class A [Member] Schedule of Related Party Transactions Schedule of Related Party Transactions [Table Text Block] Non-cash operating, investing, and financing activities: Noncash Investing and Financing Items [Abstract] Related Party Transactions [Abstract] Net increase in cash, cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Total other income (expense) Nonoperating Income (Expense) Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Basic (in shares) Weighted-average shares of Class A common stock outstanding – Basic (in shares) Weighted Average Number of Shares Outstanding, Basic Expenses Costs and Expenses [Abstract] Subsequent Events [Abstract] Ownership [Axis] Ownership [Axis] Foreign currency translation adjustment Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Sale of Stock [Domain] Sale of Stock [Domain] Class B2 Class B2 Unit [Member] Class B2 Unit Schedule of Future Minimum Lease Payments of Operating Leases Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Ownership [Domain] Ownership [Domain] Plan Name [Domain] Plan Name [Domain] Revenues Revenue from Contract with Customer [Text Block] Total stockholders' equity / partners' capital Total stockholders' equity, beginning balance Total stockholders' equity, ending balance Total stockholders' equity / partners' capital Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Organization Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Partner Type of Partners' Capital Account, Name [Domain] Partner Type of Partners' Capital Account, Name [Domain] Proceeds from IPO, net of underwriting discount Proceeds from Issuance Initial Public Offering Additional paid-in capital Additional Paid in Capital FY2022 Finite-Lived Intangible Asset, Expected Amortization, Year One Total revenues Total revenues Revenues FY2023 Operating Leases, Future Minimum Payments, Due in Three Years Class of Stock [Axis] Class of Stock [Axis] Income tax expense Income Tax Expense (Benefit) FY2025 Operating Leases, Future Minimum Payments, Due in Five Years Schedule of Unvested Restricted Stock Units Activity Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] 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 Equivalents, Restricted Cash and Restricted Cash Equivalents Purchases of marketable securities Payments to Acquire Marketable Securities Membership ownership percentage Sale of Stock, Percentage of Ownership after Transaction Accounting Standards Update and Change in Accounting Principle [Table] Accounting Standards Update and Change in Accounting Principle [Table] Total liabilities Financial and Nonfinancial Liabilities, Fair Value Disclosure Diluted (in dollars per share) Diluted (in dollars per share) Earnings Per Share, Diluted FY2022 Operating Leases, Future Minimum Payments, Due in Two Years Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Local Phone Number Local Phone Number Common stock, number of votes Common Stock, Number of Votes Common Stock, Number of Votes 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] Numerator: Net Income (Loss) Available to Common Stockholders, Diluted [Abstract] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Entity Address, Address Line One Entity Address, Address Line One Entity Address, Address Line Two Entity Address, Address Line Two Deferred revenue Contract with Customer, Liability Related Party Transaction [Domain] Related Party Transaction [Domain] Other assets and receivables Increase (Decrease) in Other Operating Assets Entity Emerging Growth Company Entity Emerging Growth Company 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 Award Type [Axis] Award Type [Axis] Number of partnership units acquired (in shares) Number Of Partnership Units Acquired Number Of Partnership Units Acquired Weighted-Average Grant-Date Fair Value Per RSU Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Less: Accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Maximum Maximum [Member] Noncontrolling Interest Noncontrolling Interest [Member] Restricted cash Restricted Cash Retained Earnings (Accumulated Deficit) Retained Earnings [Member] Effective tax rate Effective Income Tax Rate Reconciliation, Percent 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] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Net cash provided by (used in) investing activities Net Cash Provided by (Used in) Investing Activities Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Award Type [Domain] Award Type [Domain] Accounts payable, accrued expenses and other liabilities Increase (Decrease) in Other Accounts Payable and Accrued Liabilities Trading Symbol Trading Symbol Revenue from related parties Revenue from Related Parties Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Earnings Per Share Earnings Per Share [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Changes in unrealized (gains) losses included in earnings related to financial liabilities still held at the reporting date Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss) Entity Shell Company Entity Shell Company Fair Value, Recurring Fair Value, Recurring [Member] Segments Segment Reporting, Policy [Policy Text Block] Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Measurement Input, Discount Rate Measurement Input, Discount Rate [Member] Statement of Financial Position [Abstract]