Selected Quarterly Financial Data (Details) (USD $) In Millions, except Per Share data	3 Months Ended								12 Months Ended
	Jul. 31, 2011	Apr. 30, 2011	Jan. 31, 2011	Oct. 31, 2010	Jul. 31, 2010	Apr. 30, 2010	Jan. 31, 2010	Oct. 31, 2009	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2009
Quarterly Financial Information Disclosure [Abstract]
Total net revenue	$ 593	$ 1,848	$ 878	$ 532	$ 537	$ 1,607	$ 837	$ 474	$ 3,851	$ 3,455	$ 3,109
Cost of revenue	164	168	180	159	152	157	178	166
All other costs and expenses	490	619	587	477	449	562	520	408
Operating income (loss) from continuing operations	(61)	1,061	111	(104)	(64)	888	139	(100)	1,007	863	683
Net income (loss) from continuing operations	(57)	688	73	(70)	(48)	576	80	(69)	634	539	447
Net income from discontinued operations	0	0	0	0	0	0	34	1	0	35	0
Net income (loss)	$ (57)	$ 688	$ 73	$ (70)	$ (48)	$ 576	$ 114	$ (68)	$ 634	$ 574	$ 447
Basic net income (loss) per share from continuing operations	$ (0.19)	$ 2.27	$ 0.24	$ (0.22)	$ (0.15)	$ 1.83	$ 0.25	$ (0.21)	$ 2.07	$ 1.71	$ 1.39
Basic net income per share from discontinued operations	$ 0.00	$ 0.00	$ 0.00	$ 0.00	$ 0.00	$ 0.00	$ 0.11	$ 0.00	$ 0.00	$ 0.11	$ 0.00
Basic net income (loss) per share	$ (0.19)	$ 2.27	$ 0.24	$ (0.22)	$ (0.15)	$ 1.83	$ 0.36	$ (0.21)	$ 2.07	$ 1.82	$ 1.39
Diluted net income (loss) per share from continuing operations	$ (0.19)	$ 2.20	$ 0.23	$ (0.22)	$ (0.15)	$ 1.78	$ 0.25	$ (0.21)	$ 2	$ 1.66	$ 1.35
Diluted net income per share from discontinued operations	$ 0.00	$ 0.00	$ 0.00	$ 0.00	$ 0.00	$ 0.00	$ 0.10	$ 0.00	$ 0.00	$ 0.11	$ 0.00
Diluted net income (loss) per share	$ (0.19)	$ 2.2	$ 0.23	$ (0.22)	$ (0.15)	$ 1.78	$ 0.35	$ (0.21)	$ 2	$ 1.77	$ 1.35