Significant Accounting Policies (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010
Significant Accounting Policies Details [Abstract]
Discount Rate Future Net Revenues			10.00%
Inventory, Net	$ 1,548		$ 1,548		$ 2,760
Earnings Per Share Reconciliation [Abstract]
Net Income (Loss)	$ 149,146	$ 162,642	$ 321,371	$ 426,509
Weighted Average Number of Shares Outstanding, Basic	152,817	152,479	152,772	152,286
Incremental Common Shares Attributable to Share-based Payment Arrangements	1,463	1,713	1,646	1,955
Weighted Average Number of Shares Outstanding, Diluted	154,280	154,192	154,418	154,241
Earnings Per Share, Basic	$ 0.98	$ 1.07	$ 2.10	$ 2.80
Earnings Per Share, Diluted	$ 0.97	$ 1.05	$ 2.08	$ 2.77
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,168	989	968	989