The cash inflow associated with the amount received from holders exercising their stock options. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (j)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph i

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 14

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3255-108585

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 18

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 19

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

- Definition

Equity-based compensation cost during the period with respect to the award, which will be recognized in income (as well as the total recognized tax benefit) or capitalized as part of the cost of an asset.

+ References+ Details

Stock-Based Compensation - Additional Information (Detail) In Millions, unless otherwise specified	12 Months Ended
	Mar. 31, 2012 Stock Options USD ($)	Mar. 31, 2012 Stock Options JPY (¥)	Mar. 31, 2011 Stock Options JPY (¥)	Mar. 31, 2010 Stock Options JPY (¥)	Mar. 31, 2012 Stock Options Minimum Year	Mar. 31, 2012 Stock Options Maximum Year	Mar. 31, 2012 Stock Compensation Plan USD ($) Point	Mar. 31, 2012 Stock Compensation Plan JPY (¥)	Mar. 31, 2011 Stock Compensation Plan JPY (¥)	Mar. 31, 2010 Stock Compensation Plan JPY (¥)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average vesting period					1.67	1.92
Weighted average exercise period					9.67	9.92
Cash received from the exercise of stock options	$ 1	¥ 55	¥ 98	¥ 77
Total intrinsic value of options exercised	0	5	19	6
Incremental stock-based compensation costs recognized			¥ 142	¥ 611			$ 4	¥ 288	¥ 255	¥ 355
Points granted							37,600	37,600
Points settled for individuals retired							17,929	17,929
Points outstanding							142,679	142,679