Stockholders' Equity (Narrative) (Details) (USD $)	0 Months Ended	3 Months Ended
	May 27, 2009	Sep. 30, 2011	Sep. 30, 2010	Aug. 24, 2011	Jun. 30, 2011	Apr. 30, 1997
Debt Instrument [Line Items]
Shares authorized to be repurchased under repurchase program				20,000,000
Common stock authorized for issuance		22,921,650
Common shares repurchased	9,952,274	4,400,000
Common shares repurchased at cost		$ 124,700,000
Number of shares repurchased pursuant to the repurchase program		18,466,205			14,114,730
Cost of shares repurchased pursuant to the repurchase program		629,338,000			504,625,000
Remaining shares that can be repurchased under repurchase program		18,100,000
Preferred stock, shares authorized		2,000,000			2,000,000	2,000,000
Preferred stock at par value		$ 0.01			$ 0.01	$ 0.01
Preferred stock shares issued		0			0
Number of securities remaining available for future issuance		5,351,788
Expected weighted average period of unrecognized compensation costs related to unvested stock-based compensation arrangements		2.7
Unrecognized compensation costs related to unvested stock-based compensation arrangements		53,900,000
Aggregate intrinsic value of the stock-based compensation arrangements exercisable		78,600,000
Aggregate intrinsic value of the stock-based compensation arrangements outstanding		163,300,000
Aggregate intrinsic value of the options exercised		5,600,000	11,600,000
Maximum number of shares subject to awards granted		3,000,000
Number of common stock shares granted		4,500,000
Maximum [Member]
Debt Instrument [Line Items]
Stock option and restricted stock units expiration period, years		7
Stock option and restricted stock units vesting period, years		4
Maximum [Member] | Employee Stock Purchase Plan [Member]
Debt Instrument [Line Items]
Employee stock purchase program offering period, months		27
Common stock shares subscribed		25,000,000
Minimum [Member]
Debt Instrument [Line Items]
Stock option and restricted stock units vesting period, years		1
Minimum [Member] | Employee Stock Purchase Plan [Member]
Debt Instrument [Line Items]
Employee stock purchase program offering period, months		3
Employee Stock Purchase Plan [Member]
Debt Instrument [Line Items]
Percentage of purchase price of common stock lower than the fair market value of common stock on the date of grant		85.00%
Percentage of purchase price of common stock lower than the fair market value of common stock on the date of purchase		85.00%
Number of securities remaining available for future issuance		775,000
Stock compensation expense		$ 500,000
June 6, 2002 Stock Repurchase Plan [Member]
Debt Instrument [Line Items]
Common shares repurchased	6,622,907.00