Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]

No definition available.

Name:	ck0001070304_FairValueAssetAndLiabilitiesMeasuredOnRecurringBasisLineItems
Namespace Prefix:	ck0001070304_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of transfer of financial instrument classified as an asset into level 3 of the fair value hierarchy.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of transfers of financial instrument classified as an asset out of level 3 of the fair value hierarchy.

+ References

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=ck0001070304_InvestmentFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=ck0001070304_LoansHeldForSaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=ck0001070304_ForeignMunicipalBondSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Fair Value Measurements - Additional Information (Detail) - Fair Value, Measurements, Recurring - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Investment funds
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Transferred from level 3 to level 1			¥ 610
Loans Held-for-Sale
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Transferred from level 2 to level 3		¥ 176,055
Foreign municipal bond securities
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Transferred from level 2 to level 3	¥ 6,818