Stockholders' Equity (Details) (USD $)	3 Months Ended				9 Months Ended					3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended			1 Months Ended
	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011	Apr. 30, 2011	Apr. 30, 2012		Apr. 30, 2011	Apr. 30, 2012 Stock Options And Restricted Stock [Member] Years	Apr. 30, 2012 Restricted Stock Units (RSUs) [Member] Years	Apr. 30, 2012 Cost of Sales [Member]	Apr. 30, 2011 Cost of Sales [Member]	Apr. 30, 2012 Cost of Sales [Member]	Apr. 30, 2011 Cost of Sales [Member]	Apr. 30, 2012 Selling and Marketing Expense [Member]	Apr. 30, 2011 Selling and Marketing Expense [Member]	Apr. 30, 2012 Selling and Marketing Expense [Member]	Apr. 30, 2011 Selling and Marketing Expense [Member]	Apr. 30, 2012 Research and Development Expense [Member]	Apr. 30, 2011 Research and Development Expense [Member]	Apr. 30, 2012 Research and Development Expense [Member]	Apr. 30, 2011 Research and Development Expense [Member]	Apr. 30, 2012 General and Administrative Expense [Member]	Apr. 30, 2011 General and Administrative Expense [Member]	Apr. 30, 2012 General and Administrative Expense [Member]	Apr. 30, 2011 General and Administrative Expense [Member]	Apr. 30, 2012 New Program [Member]	May 31, 2012 Dividend Declared [Member]
Stockholders' Equity (Textuals)
Common stock repurchased, share					14,973,000		23,349,000
Common stock repurchased, value					$ 793,000,000		$ 1,110,000,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount																										1,800,000,000
Common Stock, Dividends, Per Share, Cash Paid	$ 0.15	$ 0.15	$ 0.15
Dividends declared per common share	$ 0.15	$ 0.15	$ 0.15	$ 0	$ 0.45		$ 0																				$ 0.15
Payments of Dividends	45,000,000	44,000,000	45,000,000	0	134,000,000		0
Dividends, Common Stock, Cash	45,000,000	44,000,000	45,000,000		134,000,000
Dividends Payable, Amount Per Share																											$ 0.15
Total share-based compensation expense
Share-based compensation expense	37,000,000			39,000,000	120,000,000		112,000,000			1,000,000	2,000,000	4,000,000	5,000,000	14,000,000	12,000,000	43,000,000	33,000,000	11,000,000	13,000,000	37,000,000	38,000,000	11,000,000	12,000,000	36,000,000	36,000,000
Income tax benefit	(12,000,000)			(14,000,000)	(39,000,000)		(39,000,000)
Decrease in net income	25,000,000			25,000,000	81,000,000		73,000,000
Decrease in net income per share:
Basic	$ 0.08			$ 0.08	$ 0.27		$ 0.24
Diluted	$ 0.08			$ 0.08	$ 0.26		$ 0.23
Activity under all share-based compensation plans [Roll Forward]
Shares available for grant, Beginning Balance			30,716,000		30,716,000
Number of shares, Balance at July 31, 2011			22,679,000		22,679,000
Weighted average exercise price per share, Balance at July 31, 2011			$ 32.38		$ 32.38
Options granted, shares available for grant					(378,000)
Options granted, number of shares					378,000
Options granted, weighted average exercise price per share	$ 51.76				$ 51.76
Restricted stock units granted, shares available for grant					(1,333,000)	[1]
Options exercised, number of shares					(6,300,000)
Options exercised, weighted average exercise price per share	$ 28.31				$ 28.31
Options canceled or expired, shares available for grant					407,000	[2]
Options canceled or expired, number of shares					(413,000)	[2]
Options canceled or expired, weighted average exercise price per share					$ 37.22	[2]
Restricted stock units forfeited, shares available for grant					1,297,000	[1],[2]
Shares available for grant, Ending Balance	30,709,000				30,709,000
Number of shares, Balance at April 30, 2012	16,344,000				16,344,000
Weighted average exercise price per share, Balance at April 30, 2012	$ 34.28				$ 34.28
Exercisable at April 30, 2012	10,600,000				10,600,000
Weighted average exercise price per share, Exercisable at April 30, 2012	$ 30.32				$ 30.32
Pool Shares Reduced For Each Share Granted					2.3
Pool Shares Increased For Each Share Forfeited					2.3
Unrecognized compensation cost related to non-vested share based compensation expense								$ 43,000,000	$ 169,000,000
Expected weighted average vesting period to recognize compensation cost related to share based compensation expense, in years								1.7	2.0
Summary of restricted stock unit activity
Nonvested at July 31, 2011			11,055,000		11,055,000
Nonvested, Weighted Average Grant Date Fair Value, at July 31, 2011			$ 37.92		$ 37.92
Granted, Number of shares					580,000
Granted, Weighted Average Grant Date Fair Value					$ 49.43
Vested, Number of Shares					(2,661,000)
Vested, Weighted Average Grant Date Fair Value					$ 28.84
Forfeited, Number of Shares					(579,000)
Forfeited, Weighted Average Grant Date Fair Value	$ 38.71				$ 38.71
Nonvested at April 30, 2012	8,395,000				8,395,000
Nonvested, Weighted Average Grant Date Fair Value, at April 30, 2012	$ 41.54				$ 41.54

[1] Under the terms of our 2005 Equity Incentive Plan as amended on January 19, 2011, 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.