Long-Term Obligations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Oct. 31, 2011	Oct. 31, 2010	Jul. 31, 2011	Mar. 12, 2007
Long Term Obligations (Textuals)
Senior notes				$ 1,000
Unamortized discounts on senior notes	1		1
Cash paid for interest on the Notes	28	28
Other long-term obligations
Total license fee payable	61		60
Total deferred rent	52		52
Long-term deferred revenue	40		40
Long-term income tax liabilities	40		42
Long-term payables	10		12
Other	1		1
Total long-term obligations	204		207
Less current portion (included in other current liabilities)	17		17
Long-term obligations due after one year	187		190
5.75 percent fixed-rate notes due 2017 [Member]
Long Term Obligations (Textuals)
Senior notes				500
Senior notes, rate				5.75%
5.40 percent fixed-rate notes due 2012 [Member]
Long Term Obligations (Textuals)
Senior notes				$ 500
Senior notes, rate				5.40%