Stockholders' Equity (Narrative) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		1 Months Ended		2 Months Ended	1 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Apr. 30, 2013 ASR March 2013 [Member]	Mar. 31, 2013 ASR March 2013 [Member]	Apr. 30, 2013 ASR March 2013 [Member]	Jul. 31, 2013 Old Rate Per Share [Member]	Jul. 31, 2013 New Rate Per Share [Member]
Stockholders' Equity [Line Items]
Dividends rate per share						$ 0.20	$ 0.24
Payments for repurchase of common stock	$ 127	$ 53		$ 150
Shares received under repurchase programs			0.2	1.2	1.4
Average price paid per share					$ 107.63
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 340