Cash Flow Information - Additional Information (Detail) In Millions	12 Months Ended
Mar. 31, 2011 USD ($)	Mar. 31, 2011 JPY (¥)	Mar. 31, 2010 JPY (¥)	Mar. 31, 2009 JPY (¥)	Mar. 31, 2010 DAIKYO JPY (¥)	Mar. 31, 2009 DAIKYO JPY (¥)
Schedule of Cash Flow, Supplemental [Line Items]
Non-cash investing activities, liabilities assumed	$ 1,719	¥ 142,906	¥ 27,688	¥ 38,120
Non-cash investing activities, common stocks issued in connection with acquisitions				1,673
Real estate under operating leases transferred from installment loans and investment in securities as a result of real estate collateral acquired from non-recourse loans	719	59,783	83,018	39,905
Non-cash investing activities, common stocks received in connection with a sale of subsidiary					26,617	9,439
Loans to affiliate	743	61,820	116,223		95,547
Investment in affiliates	3,747	311,556	293,488		25,828
Investment in affiliates, increased during the period			¥ 121,375		¥ 3,789

Schedule of Cash Flow, Supplemental [Line Items]

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Long-Term advances receivable form a party that is affiliated with the reporting entity by means of direct or indirect ownership. This does not include advances to clients.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Paragraph 2
-Article 6

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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment losses recognized.

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The net of the gross additions and gross reductions to the investment in and advance to the affiliate.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 14
-Paragraph 1
-Article 12

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The total amount of [all] liabilities that an Entity assumes in acquiring a business or in consideration for an asset received in a noncash (or part noncash) acquisition. Noncash is defined as transactions during a period that affect recognized assets or liabilities but that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 32

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The value of the consideration received for selling an asset or business through a noncash (or part noncash) transaction. Noncash is defined as transactions during a period that affect recognized assets or liabilities but that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

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The fair value of stock issued in noncash financing activities.

+ References

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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 32

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Value of real estate transferred in noncash transactions during the reporting period.

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-Name Statement of Financial Accounting Standard (FAS)
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