Stockholders' Equity - Stock Options Granted (Details) - Jun. 30, 2015 - $ / shares	Total	Total
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted		9,948,220
Options Outstanding	5,192,882	5,192,882
Options Exercisable	2,214,540	2,214,540
April 21, 2015 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted	893,220
Option Exercise (Strike) Price	$ 42.00
Closing Stock Price on Date of Grant	$ 41.26	$ 41.26
Options Outstanding	880,842	880,842
Options Exercisable	0	0
April 22, 2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted	955,000
Option Exercise (Strike) Price	$ 56.00
Closing Stock Price on Date of Grant	$ 50.53	$ 50.53
Options Outstanding	807,500	807,500
Options Exercisable	5,000	5,000
April 16, 2013 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted	205,000
Option Exercise (Strike) Price	$ 54.00
Closing Stock Price on Date of Grant	$ 49.25	$ 49.25
Options Outstanding	137,500	137,500
Options Exercisable	0	0
April 17, 2012 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted	1,235,000
Option Exercise (Strike) Price	$ 54.00
Closing Stock Price on Date of Grant	$ 49.01	$ 49.01
Options Outstanding	1,060,000	1,060,000
Options Exercisable	243,750	243,750
April 19, 2011 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted	410,000
Option Exercise (Strike) Price	$ 35.00
Closing Stock Price on Date of Grant	$ 31.78	$ 31.78
Options Outstanding	268,800	268,800
Options Exercisable	143,800	143,800
April 20, 2010 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted	530,000
Option Exercise (Strike) Price	$ 30.00
Closing Stock Price on Date of Grant	$ 27.13	$ 27.13
Options Outstanding	226,500	226,500
Options Exercisable	129,000	129,000
April 21, 2009 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted	790,000
Option Exercise (Strike) Price	$ 27.00
Closing Stock Price on Date of Grant	$ 17.61	$ 17.61
Options Outstanding	303,900	303,900
Options Exercisable	211,400	211,400
April 15, 2008 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted	550,000
Option Exercise (Strike) Price	$ 27.00
Closing Stock Price on Date of Grant	$ 24.35	$ 24.35
Options Outstanding	161,000	161,000
Options Exercisable	134,750	134,750
April 17, 2007 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted	4,380,000
Option Exercise (Strike) Price	$ 22.50
Closing Stock Price on Date of Grant	$ 20.15	$ 20.15
Options Outstanding	1,346,840	1,346,840
Options Exercisable	1,346,840	1,346,840