v3.25.3

Income Taxes (Details) - USD ($)	3 Months Ended		6 Months Ended
Income Taxes (Details) - USD ($)	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Increase in deferred tax assets, exchange of partnership units for common stock	$ 8,800,000
Increase in due to related parties, tax receivable agreements	$ 7,400,000
Percentage of total net cash savings due to exchanging limited partners	85.00%		85.00%
Increase (decrease) in deferred tax liabilities, exchange of partnership units for common stock	$ (1,700,000)
Payments to related parties under Tax Receivable Agreements	0	$ 0	$ 11,494,000	$ 9,802,000
Due to related parties, tax receivable agreements	321,600,000		321,600,000
impact on effective tax rate for equity-based compensation expense	$ 125,100,000		$ 150,300,000
Effective tax rate	14.80%	8.20%	15.60%	10.20%
Unrecognized tax benefits	$ 0		$ 0
Changes to uncertain tax positions	0		$ 0
Exchange of Partnership Units for Common Stock
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Increase (decrease) in valuation allowance	$ 2,400,000

Due To Related Parties, Tax Receivable Agreements

+ References

No definition available.

+ Details

Name:	step_DueToRelatedPartiesTaxReceivableAgreements
Namespace Prefix:	step_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Increase (Decrease) In Deferred Tax Assets, Exchange Of Partnership Units For Common Stock

+ References

No definition available.

+ Details

Name:	step_IncreaseDecreaseInDeferredTaxAssetsExchangeOfPartnershipUnitsForCommonStock
Namespace Prefix:	step_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Increase (Decrease) In Deferred Tax Liabilities, Exchange Of Partnership Units For Common Stock

+ References

No definition available.

+ Details

Name:	step_IncreaseDecreaseInDeferredTaxLiabilitiesExchangeOfPartnershipUnitsForCommonStock
Namespace Prefix:	step_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Increase (Decrease) In Due To Related Parties, Tax Receivable Agreements

+ References

No definition available.

+ Details

Name:	step_IncreaseDecreaseInDueToRelatedPartiesTaxReceivableAgreements
Namespace Prefix:	step_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Incremental Net Cash Tax Savings Due To Exchanging Limited Partners, Percent

+ References

No definition available.

+ Details

Name:	step_IncrementalNetCashTaxSavingsDueToExchangingLimitedPartnersPercent
Namespace Prefix:	step_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Payments To Related Parties, Tax Receivable Agreements

+ References

No definition available.

+ Details

Name:	step_PaymentsToRelatedPartiesTaxReceivableAgreements
Namespace Prefix:	step_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 231
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482663/740-10-55-231

+ Details

Name:	us-gaap_EffectiveIncomeTaxRateContinuingOperations
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of reported income tax expense (benefit) in excess of (less than) expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to nondeductible expense for award under share-based payment arrangement. Includes, but is not limited to, expense determined to be nondeductible upon grant or after for award under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 231
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482663/740-10-55-231

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12A
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12A

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12

+ Details

Name:	us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of the unrecognized tax benefit of a position taken for which it is reasonably possible that the total amount thereof will significantly increase or decrease within twelve months of the balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-15

+ Details

Name:	us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleAmountOfUnrecordedBenefit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Subparagraph (d)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-15

+ Details

Name:	us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of unrecognized tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 217
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482663/740-10-55-217

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-15A

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 10B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482525/740-10-45-10B

+ Details

Name:	us-gaap_UnrecognizedTaxBenefits
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of increase (decrease) in the valuation allowance for a specified deferred tax asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

+ Details

Name:	us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_ValuationAllowanceByDeferredTaxAssetAxis=step_ExchangeOfPartnershipUnitsForCommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

StepStone Group Inc. 10-Q