Stockholders' Equity 2 (Details) (USD $)	1 Months Ended	3 Months Ended	5 Months Ended	12 Months Ended				12 Months Ended				1 Months Ended	12 Months Ended	9 Months Ended	1 Months Ended
	Jan. 31, 2012	Jun. 30, 2012	Mar. 31, 2013	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011	Mar. 31, 2013 Treasury Stock	Mar. 31, 2012 Treasury Stock	Mar. 31, 2013 Additional Paid-in Capital	Mar. 31, 2012 Additional Paid-in Capital	Jan. 31, 2012 Current Stock Repurchase Program [Member]	Mar. 31, 2013 Current Stock Repurchase Program [Member]	Dec. 31, 2011 Previously Approved Stock Repurchase Program [Member]	Jan. 31, 2012 Accelerated Share Repurchase Agreement [Member]
Stock Repurchase Program [Line Items]
Stock repurchase program, Authorized amount												$ 1,500,000,000			$ 500,000,000
Remaining authorized common stock repurchase amount													505,000,000	232,000,000
Accelerated share repurchase, Value				0	500,000,000			125,000,000	375,000,000	(125,000,000)	125,000,000
Stockholders' Equity (Textual) [Abstract]
Capital allocation program, Authorized amount	2,500,000,000
Number of initial shares received under accelerated share repurchase agreement					15,000,000
Number of additional shares received under accelerated share repurchase agreement		3,700,000
Total shares of common stock repurchased excluding ASR				20,000,000
Value of common stock repurchased excluding ASR				495,000,000
Accumulated other comprehensive loss			155,000,000	155,000,000	108,000,000	65,000,000
Amount of loss reclassified into interest expense, net relating to sale of marketable securities					less than $1 million	less than $1 million
Amount of loss reclassified into interest expense, net relating to cash flow hedges						4,000,000
Expected annual dividend per share					$ 1.00		$ 0.20
Rights plan, Beneficial ownership with exclusion			20% or more
Rights plan, Grandfathered maximum shares			126,562,500
Rights plan, Grandfathered affiliates percentage of shares outstanding			0.10%
Rights plan, Beneficial ownership			more than 50%
Rights plan, Effect of tender offer			20% or more
Rights plan, Shares			0.001 shares
Rights plan, Purchase price			100
Rights plan, Exercise price			$ 100
Rights plan, Qualifying offer			10.00%
Rights plan, Redemption price and term			$0.001 per Right, expire November 30, 2015