Long-Term Obligations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Oct. 31, 2012	Oct. 31, 2011	Jul. 31, 2012	Mar. 12, 2007
Long Term Obligations (Textuals)
Senior notes				$ 1,000
Cash paid for interest on the Notes	14	28
Other long-term obligations
Total license fee payable	55		54
Total deferred rent	53		53
Long-term deferred revenue	40		42
Long-term income tax liabilities	42		41
Other	5		5
Total long-term obligations	195		195
Less current portion (included in other current liabilities)	(19)		(19)
Long-term obligations due after one year	176		176
5.40 percent fixed-rate notes due 2012 [Member]
Long Term Obligations (Textuals)
Senior notes				500
Senior notes, rate				5.40%
5.75 percent fixed-rate notes due 2017 [Member]
Long Term Obligations (Textuals)
Senior notes				$ 500
Senior notes, rate				5.75%