Share Repurchases (Narrative) (Details) (USD $) In Millions	1 Months Ended				3 Months Ended		5 Months Ended	7 Months Ended	8 Months Ended
	Feb. 28, 2011	Aug. 31, 2010	Feb. 28, 2010	Nov. 30, 2009	Apr. 30, 2011	May 01, 2010	Mar. 31, 2010	Aug. 31, 2010	Mar. 31, 2011
Share Repurchases
Share repurchases, authorized amount	$ 2,000	$ 750	$ 1,000	$ 500
Share repurchases, utilized amount					509		500	1,000	750
Share repurchases, shares repurchased from the Fisher family						0.5
Share repurchases, value of shares repurchased from the Fisher family						10
Total share repurchases paid for					$ 30