Significant Accounting Policies (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Significant Accounting Policies Details [Abstract]
Discount Rate Future Net Revenues			10.00%
Earnings Per Share Reconciliation [Abstract]
Net Income (Loss)	$ 106,049	$ 116,377	$ 207,763	$ 132,811
Weighted Average Number of Shares Outstanding, Basic	153,179	152,948	153,110	152,947
Incremental Common Shares Attributable to Share-based Payment Arrangements	1,828	1,565	1,805	1,450
Weighted Average Number of Shares Outstanding, Diluted	155,007	154,513	154,915	154,397
Earnings Per Share, Basic	$ 0.69	$ 0.76	$ 1.36	$ 0.87
Earnings Per Share, Diluted	$ 0.68	$ 0.75	$ 1.34	$ 0.86
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,196	1,332	1,707	2,014