Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2016	Mar. 31, 2016
Statement of Financial Position [Abstract]
Accumulated depreciation	$ 830	$ 832
Preferred stock, No par value (in dollars per share)	$ 0	$ 0
Preferred stock, Shares authorized	10,000,000	10,000,000
Preferred stock, Shares issued	0	0
Preferred stock, Shares outstanding	0	0
Common stock, Par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, Shares authorized	1,100,000,000	1,100,000,000
Common stock, Shares issued	589,695,081	589,695,081
Common stock, Shares outstanding	414,125,562	412,596,452
Treasury stock, Shares	175,569,519	177,098,629

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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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.

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