Condensed Consolidated Statements of Comprehensive Income (Loss) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Oct. 31, 2012	Oct. 31, 2011
Statement of Other Comprehensive Income [Abstract]
Net loss	$ (19)	$ (64)
Other comprehensive income (loss), net of income taxes:
Unrealized losses on available-for-sale debt securities	0	(1)
Unrealized gains on available-for-sale equity securities	3	0
Foreign currency translation gains (losses)	1	(5)
Total other comprehensive income (loss), net	4	(6)
Comprehensive loss	$ (15)	$ (70)