Subsequent Events (Details) (USD $)	1 Months Ended	3 Months Ended							9 Months Ended
	Jan. 24, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Dec. 31, 2011
Subsequent Events [Abstract]
Capital allocation program	$ 2,500,000,000
Expected annual dividend, per share	$ 1.00		$ 0.20						$ 0.20
Stock repurchase program, authorized amount	1,500,000,000
Remaining authorized amount of common stock under common stock repurchase program									$ 232,000,000
Dividend Per Share		$ 0.25	$ 0.05	$ 0.05	$ 0.05	$ 0.04	$ 0.04	$ 0.04