Securitizations and Variable Interest Entities - Type and Carrying Value of Financial Assets (Detail) (JPY ¥)	Mar. 31, 2013	Mar. 31, 2012
Liabilities [Abstract]
Long-term borrowings	¥ 7,592,368,000,000	¥ 8,504,840,000,000
Transferred to SPEs [Member]
Trading assets
Equities	72,000,000,000	116,000,000,000
Debt securities	86,000,000,000	84,000,000,000
Mortgage and mortgage-backed securities	24,000,000,000	27,000,000,000
Long-term loans receivable	8,000,000,000	21,000,000,000
Total	190,000,000,000	248,000,000,000
Liabilities [Abstract]
Long-term borrowings	¥ 177,000,000,000	¥ 223,000,000,000

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents securitized, pay-through debt securities collateralized by real estate mortgage loans (mortgages) as of the balance sheet date which have been categorized as available-for-sale.

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- Definition

The sum of the carrying amounts, as of the date of the latest financial statement presented, of loans receivable which are owned but transferred to serve as collateral for the payment of related debt obligations, primarily secured borrowings and repurchase agreements, and for which the transferees are not permitted to sell or re-pledge them to an unrelated party.

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- Definition

Debt securities that are bought and held principally for the purpose of selling them in the near term (thus held for only a short period of time) or for debt securities formerly categorized as available-for-sale or held-to-maturity which the entity held as of the date it opted to account for such securities at fair value. An enterprise may also categorize such a security as trading without the intent to sell it in the near term assuming the decision to categorize the security as trading occurred at acquisition.

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-Glossary Trading Securities

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- Definition

Total common and preferred stock (which is not mandatorily redeemable, redeemable at the option of the holder, or in any other way classified as liability) equity securities that are bought and held principally for the purpose of selling them in the near term (thus held for only a short period of time) or for equity securities formerly categorized as available-for-sale or held-to-maturity which the entity held as of the date it opted to account for such securities at fair value. An enterprise may also categorize such a security as trading without the intent to sell it in the near term assuming the decision to categorize the security as trading occurred at acquisition.

+ References

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