Stockholders' Equity (Narrative) (Details) (USD $) In Millions	1 Months Ended		6 Months Ended	120 Months Ended	1 Months Ended
	Aug. 31, 2011 June 2001 Buyback Plan [Member]	Jun. 30, 2001 June 2001 Buyback Plan [Member]	Jun. 30, 2011 June 2001 Buyback Plan [Member]	Jun. 30, 2011 June 2001 Buyback Plan [Member]	Apr. 30, 2011 April 2011 Buyback Plan [Member]
Shares buyback plan, authorized limit		$ 2,000			$ 2,000
Repurchased and retired			272	1,484
Repurchased and retired, shares			5.0	30.9
Stock buyback program	$ 400