Significant Accounting Policies (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Significant Accounting Policies Details [Abstract]
Discount Rate Future Net Revenues									10.00%
Inventory, Net	$ 1,164				$ 2,760				$ 1,164	$ 2,760
Earnings Per Share Reconciliation
Net earnings (loss)	$ 131,831	$ 149,146	$ 103,505	$ 68,720	$ 37,948	$ 162,642	$ 61,493	$ 202,376	$ 453,202	$ 464,459	$ (451,053)
Weighted average common shares outstanding - basic									152,754	152,346	151,367
Effect of dilutive instruments									1,582	1,907	0
Weighted average common shares outstanding - fully diluted									154,336	154,253	151,367
Net (loss) income per common share - basic	$ 0.86	$ 0.98	$ 0.68	$ 0.45	$ 0.25	$ 1.07	$ 0.40	$ 1.33	$ 2.97	$ 3.05	$ (2.98)
Net (loss) income per common share - fully diluted	$ 0.86	$ 0.97	$ 0.67	$ 0.44	$ 0.25	$ 1.05	$ 0.40	$ 1.31	$ 2.94	$ 3.01	$ (2.98)
Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount									1,030	1,214	2,200