Condensed Consolidated Statements of Comprehensive Loss (USD $) In Millions, unless otherwise specified	3 Months Ended
	Oct. 31, 2013	Oct. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (11)	$ (19)
Other comprehensive income (loss), net of income taxes:
Unrealized gains on available-for-sale debt securities	2	0
Unrealized gains on available-for-sale equity securities	(1)	3
Foreign currency translation gains (losses)	(2)	1
Total other comprehensive income (loss), net	(1)	4
Comprehensive loss	$ (12)	$ (15)