Stockholders' Equity (Details) (USD $)	3 Months Ended
	Oct. 31, 2012		Oct. 31, 2011	Oct. 31, 2012 Stock Options [Member]	Oct. 31, 2012 Restricted Stock Units (RSUs) [Member]	Oct. 31, 2012 Cost of revenue [Member]	Oct. 31, 2011 Cost of revenue [Member]	Oct. 31, 2012 Selling and marketing [Member]	Oct. 31, 2011 Selling and marketing [Member]	Oct. 31, 2012 Research and development [Member]	Oct. 31, 2011 Research and development [Member]	Oct. 31, 2012 General and administrative [Member]	Oct. 31, 2011 General and administrative [Member]	Oct. 31, 2012 New Program [Member]	Nov. 30, 2012 Dividend Declared [Member]
Stockholders' Equity (Textuals)
Common stock repurchased, share	1,700,000		5,200,000
Common stock repurchased, value	$ 100,000,000		$ 255,000,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount														1,600,000,000
Common Stock, Dividends, Per Share, Cash Paid	$ 0.17
Dividends declared per common share (dollars per share)	$ 0.17		$ 0.15
Payments of Dividends	50,000,000		45,000,000
Dividends Payable, Amount Per Share															$ 0.17
Total share-based compensation expense
Share-based compensation expense	49,000,000		40,000,000			2,000,000	1,000,000	18,000,000	14,000,000	14,000,000	12,000,000	15,000,000	13,000,000
Income tax benefit	(17,000,000)		(13,000,000)
Increase in net loss	32,000,000		27,000,000
Increase in net loss per share:
Basic (dollars per share)	$ 0.11		$ 0.09
Diluted (dollars per share)	$ 0.11		$ 0.09
Share-based awards available for grant
Shares Available for Grant, Beginning Balance	21,760,000
Options granted	(76,000)
Restricted stock units granted	(512,000)	[1]
Share-based awards canceled/forfeited/expired	1,002,000	[1],[2]
Shares Available for Grant, Ending Balance	22,174,000
Pool Shares Reduced For Each Share Granted	2.3
Pool Shares Increased For Each Share Forfeited	2.3
Summary of stock option activity
Number of shares, Beginning Balance	18,061,000
Weighted average exercise price per share, Beginning Balance	$ 37.49
Options granted, number of shares	76,000
Options granted, weighted average exercise price per share	$ 59.71
Options exercised, number of shares	(2,051,000)
Options exercised, weighted average exercise price per share	$ 32.01
Options canceled or expired, number of shares	(222,000)
Options canceled or expired, weighted average exercise price per share	$ 38.00
Number of shares, Ending Balance	15,864,000
Weighted average exercise price per share, Ending Balance	$ 38.30
Exercisable	9,716,000
Weighted average exercise price per share, Exercisable
Unrecognized compensation cost related to non-vested share based compensation expense				$ 63,000,000	$ 244,000,000
Expected weighted average vesting period to recognize compensation cost related to share based compensation expense, in years				2 years 2 months	2 years 3 months
Summary of restricted stock unit activity
Nonvested at beginning of period	9,607,000
Nonvested, Weighted Average Grant Date Fair Value, at beginning of period	$ 46.79
Granted, Number of shares	222,000
Granted, Weighted Average Grant Date Fair Value	$ 59.66
Vested, Number of Shares	(517,000)
Vested, Weighted Average Grant Date Fair Value	$ 35.03
Forfeited, Number of Shares	(369,000)
Forfeited, Weighted Average Grant Date Fair Value	$ 46.33
Nonvested at end of period	8,943,000
Nonvested, Weighted Average Grant Date Fair Value, at end of period	$ 47.81

[1] Under the terms of our Amended and Restated 2005 Equity Incentive Plan, as amended through July 24, 2012 (2005 Equity Incentive Plan), RSUs granted from the pool of shares available for grant on or after November 1, 2010 reduce the pool by 2.3 shares for each share granted. RSUs forfeited and returned to the pool of shares available for grant increase the pool by 2.3 shares for each share forfeited.

[2] Stock options and restricted stock units canceled, expired or forfeited under our 2005 Equity Incentive Plan, are returned to the pool of shares available for grant. Stock options and restricted stock units canceled, expired or forfeited under older expired plans are not returned to the pool of shares available for grant.