Fair Value Measurements (Recorded Amounts of Major Assets Measured at Fair Value on Nonrecurring Basis) (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	¥ 151,601	¥ 63,272
Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	235	238
Real estate collateral-dependent loans (net of allowance for credit losses)	6,972	10,679
Investment in operating leases and property under facility operations	59,847	6,740
Certain equity securities	9,451	10,486
Certain investments in affiliates	2,846	11,413
Certain reporting units including goodwill	192	775
Certain intangible assets acquired in a business combination fair value	98,014
Assets measured at fair value on a nonrecurring basis	177,557	40,331
Fair Value, Measurements, Nonrecurring \| Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	0	0
Real estate collateral-dependent loans (net of allowance for credit losses)	0	0
Investment in operating leases and property under facility operations	0	0
Certain equity securities	0	0
Certain investments in affiliates	0	8,799
Certain reporting units including goodwill	0	0
Certain intangible assets acquired in a business combination fair value	0
Assets measured at fair value on a nonrecurring basis	0	8,799
Fair Value, Measurements, Nonrecurring \| Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	235	238
Real estate collateral-dependent loans (net of allowance for credit losses)	0	0
Investment in operating leases and property under facility operations	262	1,806
Certain equity securities	9,451	6,909
Certain investments in affiliates	0	0
Certain reporting units including goodwill	0	0
Certain intangible assets acquired in a business combination fair value	0
Assets measured at fair value on a nonrecurring basis	9,948	8,953
Fair Value, Measurements, Nonrecurring \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	0	0
Real estate collateral-dependent loans (net of allowance for credit losses)	6,972	10,679
Investment in operating leases and property under facility operations	59,585	4,934
Certain equity securities	0	3,577
Certain investments in affiliates	2,846	2,614
Certain reporting units including goodwill	192	775
Certain intangible assets acquired in a business combination fair value	98,014
Assets measured at fair value on a nonrecurring basis	¥ 167,609	¥ 22,579

Certain intangible assets acquired in a business combination fair value.

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- Definition

Investment in operating leases and property under facility operations.

+ References

No definition available.

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- Definition

Real estate collateral-dependent loans (net allowance probable loan losses).

+ References

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- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258

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- Definition

Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=123594786&loc=SL75136599-209740

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- 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

No definition available.

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- Definition

Fair value portion of asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258

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- Definition

Fair value portion of investments in an entity not consolidated. Includes, but is not limited to, investments in an entity that is affiliated with the reporting entity by means of direct or indirect ownership, an entity in which the reporting entity shares control of the entity with another party or group, an entity which the company has significant influence, but does not have control and subsidiaries that are not required to be consolidated and are accounted for using the equity or cost method.

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- Definition

Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

+ References

No definition available.

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