Investments in Debt, Equity Securities and Other Investments (Proceeds from Sales of Available-for-sale Securities and Related Gross Realized Gains and Losses) (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Proceeds from sales of available-for-sale securities	¥ 39,118	¥ 22,766	¥ 24,440
Gross realized gains	20,352	¥ 494	3,323
Gross realized losses	¥ 1		¥ 460

This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563

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- Definition

The total amount of proceeds received for the sale of securities, categorized neither as held-to-maturity nor trading securities, during the reporting period.

+ References

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- Definition

This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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- References

No definition available.

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