Stockholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Jun. 30, 2017	Apr. 30, 1997
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total number of shares repurchased pursuant to the repurchase program	41,086,234		41,086,234
Total cost of shares repurchased pursuant to the repurchase program	$ 1,546,611		$ 1,546,611
Common shares repurchased	0	0
Additional shares that can be repurchased under the approved share repurchase program	13,600,000
Preferred stock, shares authorized	2,000,000		2,000,000
Preferred stock at par value	$ 0.01		$ 0.01
Preferred stock, shares issued	0		0
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				$ 0.01
Preferred stock, shares issued	0		0
Preferred stock, shares outstanding	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
Number of securities remaining available for future issuance	11,600,000
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of securities remaining available for future issuance	800,000
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
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