Consolidated Balance Sheets (Parenthetical)	Mar. 31, 2011	Mar. 31, 2010
Consolidated Balance Sheets
Common stock, shares authorized	4,950,000,000	4,950,000,000
Common stock, shares issued	2,453,053,497	2,453,053,497
Treasury stock, shares	382,760,101	382,448,008

The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 30
-Article 5

+ Details

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- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 30
-Article 5

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
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- Details

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- Definition

Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 29, 30
-Article 5

+ Details

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Period Type:	instant