Fair Value (Carrying Value of Assets Measured at Fair Value on Nonrecurring Basis by Level) (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Line Items]
Goodwill	¥ 490,344	¥ 296,772	¥ 303,611
Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Line Items]
Investment securities	54,635	26,637
Loans	633,844	616,360
Loans held for sale	472,711	439,361
Collateral dependent loans	161,133	176,999
Premises and equipment	6,950	11,835
Intangible assets	5,174	309
Goodwill	0	184,364
Other assets	50,654	207,595
Investments in equity method investees	29,503	191,064
Other	21,151	16,531
Total	751,257	1,047,100
Investment securities valued at net asset value	18,037	33,595
Unfunded commitments related to investment securities valued at net asset value	24,208	23,029
Fair Value, Measurements, Nonrecurring \| Level 1
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Line Items]
Investment securities	0	0
Loans	2,271	1,917
Loans held for sale	0	0
Collateral dependent loans	2,271	1,917
Premises and equipment	0	0
Intangible assets	0	0
Goodwill	0	0
Other assets	0	178,592
Investments in equity method investees	0	178,592
Other	0	0
Total	2,271	180,509
Fair Value, Measurements, Nonrecurring \| Level 2
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Line Items]
Investment securities	9,460	13,366
Loans	5,201	3,388
Loans held for sale	0	0
Collateral dependent loans	5,201	3,388
Premises and equipment	0	0
Intangible assets	0	0
Goodwill	0	0
Other assets	32,481	0
Investments in equity method investees	27,801	0
Other	4,680	0
Total	47,142	16,754
Fair Value, Measurements, Nonrecurring \| Level 3
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Line Items]
Investment securities	45,175	13,271
Loans	626,372	611,055
Loans held for sale	472,711	439,361
Collateral dependent loans	153,661	171,694
Premises and equipment	6,950	11,835
Intangible assets	5,174	309
Goodwill	0	184,364
Other assets	18,173	29,003
Investments in equity method investees	1,702	12,472
Other	16,471	16,531
Total	¥ 701,844	¥ 849,837

Fair value portion of collateral dependent loans.

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Fair value portion of intangible assets excluding goodwill.

+ References

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Other Assets, Excluding Held For Sale, Fair Value Disclosure

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Fair value of investment other than investment in equity security, investment in debt security and equity method investment. Includes, but is not limited to, investment in certain entities that calculate net asset value per share. Example includes, but is not limited to, investment in hedge fund, venture capital fund, private equity fund, and real estate partnership or fund.

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

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Fair value portion of investments accounted under the equity method.

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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.

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The amount of unfunded commitments for which the entity is obligated, to those certain investments for which net asset value per share is calculated (including by unit, membership interest, or other equity (ownership interest) unit measure) (alternative investments).

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

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

+ References

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Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

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Fair value portion of other assets.

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Fair value portion of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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