Condensed Consolidated Statements of Comprehensive Income (Loss) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2013	Jan. 31, 2012
Statement of Other Comprehensive Income [Abstract]
Net income	$ 71	$ 118	$ 52	$ 54
Other comprehensive income (loss), net of income taxes:
Unrealized losses on available-for-sale debt securities	0	0	0	(1)
Unrealized gains on available-for-sale equity securities	0	0	3	0
Foreign currency translation gains (losses)	0	0	1	(5)
Total other comprehensive income (loss), net	0	0	4	(6)
Comprehensive income	$ 71	$ 118	$ 56	$ 48