Changes in Components of Accumulated Other Comprehensive Income (Loss) (Parenthetical) (Detail) In Millions	12 Months Ended
Mar. 31, 2011 USD ($)	Mar. 31, 2011 JPY (¥)	Mar. 31, 2010 JPY (¥)	Mar. 31, 2009 JPY (¥)
Cumulative effect of applying new accounting standards for the consolidation of variable interest entities, tax	$ 27	¥ 2,265
Net unrealized gains (losses) on investment in securities, tax	(29)	(2,379)	(6,610)	30,939
Reclassification adjustment included in net income, tax	(39)	(3,289)	(1,206)	(3,406)
Defined benefit pension plans, tax	16	1,339	(4,567)	8,169
Reclassification adjustment included in net income, tax	1	88	(358)	193
Foreign currency translation adjustments, tax	3	245	(4,487)	2,309
Reclassification adjustment included in net income, tax	0	(31)	(235)	(198)
Net unrealized gains (losses) on derivative instruments, tax	6	488	743	274
Reclassification adjustment included in net income, tax	$ (2)	¥ (150)	¥ 323	¥ 116

- Definition

Other Comprehensive Income, Defined Benefit Plans Net Unamortized Gain (Loss) Arising During Period, Tax, Attributable to Parent

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- Definition

Other Comprehensive Income, Foreign Currency Translation Gain (Loss) Arising During Period, Tax, Attributable to Parent

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- Definition

Other Comprehensive Income, Foreign Currency Translation Reclassification Adjustment Realized upon Sale or Liquidation, Tax, Attributable to Parent

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- Definition

Other Comprehensive Income, Reclassification Adjustment for Sale of Securities Included in Net Income, Tax, Attributable to Parent

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- Definition

Other Comprehensive Income, Reclassification Adjustment on Derivatives Included in Net Income, Tax, Attributable to Parent

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- Definition

Other Comprehensive Income, Reclassification of Defined Benefit Plans Net Gain (Loss) Recognized in Net Periodic Benefit Cost, Tax, Attributable to Parent

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- Definition

Other Comprehensive Income, Unrealized Gain (Loss) on Derivatives Arising During Period, Tax, Attributable to Parent

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- Definition

Other Comprehensive Income, Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax, Attributable to Parent

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- Definition

The sum of income taxes on the cumulative effects of a change in accounting principle recognized in a period as other comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 154
-Paragraph 9, 17

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