Stockholders' Equity (Narrative) (Details) | 3 Months Ended | 6 Months Ended | | |
Dec. 31, 2015USD ($)$ / sharesshares | Dec. 31, 2014USD ($)shares | Dec. 31, 2015USD ($)$ / sharesshares | Dec. 31, 2014USD ($) | Jun. 30, 2015USD ($)$ / sharesshares | Apr. 30, 1997$ / sharesshares |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | |
Common shares repurchased | 700,000 | 700,000 | | | | |
Cost of common shares repurchased | $ | $ 40,100,000 | $ 33,500,000 | | | | |
Additional shares that can be repurchased under the approved share repurchase program | 13,600,000 | | 13,600,000 | | | |
Number of shares repurchased pursuant to the repurchase program | 41,086,234 | | 41,086,234 | | 39,186,234 | |
Cost of shares repurchased pursuant to the repurchase program | $ | $ 1,546,611,000 | | $ 1,546,611,000 | | $ 1,444,554,000 | |
Preferred stock, shares authorized | 2,000,000 | | 2,000,000 | | 2,000,000 | |
Preferred stock at par value | $ / shares | $ 0.01 | | $ 0.01 | | $ 0.01 | |
Preferred stock, shares issued | 0 | | 0 | | 0 | |
Unrecognized compensation costs related to unvested stock-based compensation arrangements | $ | $ 87,800,000 | | $ 87,800,000 | | | |
Expected weighted average period of unrecognized compensation costs related to unvested stock-based compensation arrangements | | | 2 years 6 months | | | |
Aggregate intrinsic value of the stock-based compensation arrangements outstanding | $ | 147,700,000 | | $ 147,700,000 | | | |
Aggregate intrinsic value of the stock-based compensation arrangements exercisable | $ | $ 41,900,000 | | 41,900,000 | | | |
Aggregate intrinsic value of the options exercised | $ | | | $ 25,300,000 | $ 28,500,000 | | |
Series A Junior Participating Preferred Stock [Member] | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | |
Preferred stock, shares authorized | | | | | | 2,000,000 |
Preferred stock at par value | $ / shares | | | | | | $ 0.01 |
Preferred stock, shares issued | 0 | | 0 | | 0 | |
Preferred stock, shares outstanding | 0 | | 0 | | 0 | |
2009 Plan [Member] | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | |
Stock option expiration period | | | 7 years | | | |
Common stock authorized for issuance | 43,700,000 | | 43,700,000 | | | |
Reduction in the number of shares of common stock available for issuance | 2.8 | | 2.8 | | | |
Maximum number of shares subject to awards granted | 3,000,000 | | 3,000,000 | | | |
Number of common stock shares granted in participant's initial year of hiring | 4,500,000 | | 4,500,000 | | | |
Number of securities remaining available for future issuance | 12,700,000 | | 12,700,000 | | | |
Employee Stock Purchase Plan [Member] | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [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 | 1,400,000 | | 1,400,000 | | | |
Minimum [Member] | 2009 Plan [Member] | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | |
Stock options and restricted stock units vesting period | | | 1 year | | | |
Minimum [Member] | Employee Stock Purchase Plan [Member] | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | |
Employee stock purchase program offering period | | | 3 months | | | |
Maximum [Member] | 2009 Plan [Member] | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | |
Stock options and restricted stock units vesting period | | | 4 years | | | |
Maximum [Member] | Employee Stock Purchase Plan [Member] | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | |
Employee stock purchase program offering period | | | 27 months | | | |
Common stock shares subscribed | $ | $ 25,000 | | $ 25,000 | | | |