Earnings Per Share (Schedule Of Computation Of Basic And Diluted Earnings Per Share) (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
Earnings Per Share [Abstract]
Net income (loss)	$ 44,093	$ 96,321	$ 99,422	$ 52,097	$ (17,268)	$ 1,910	$ 27,605	$ 10,143	$ 291,933		$ 22,390		$ 63,846
Common shares									(184,383)		(65,260)		(25,511)
Unvested shares									(1,592)		(1,492)		(382)
Undistributed (overdistributed) earnings									$ 105,958		$ (44,362)		$ 37,953
Common shares, basic									78,992		28,440		13,304
Distributed earnings, basic									$ 2.33		$ 2.29		$ 1.92
Undistributed (overdistributed) earnings									$ 1.33		$ (1.56)		$ 2.84
Basic earnings per common share									$ 3.66		$ 0.73		$ 4.76
Net effect of dilutive warrants									1	[1]	10	[1]	16	[1]
Diluted weighted average shares outstanding									78,993		28,450		13,320
Distributed earnings, diluted									$ 2.33		$ 2.29		$ 1.92
Undistributed earnings, diluted									$ 1.33		$ (1.56)		$ 2.83
Diluted earnings per common share	$ 0.53	$ 1.16	$ 1.20	$ 0.74	$ (0.38)	$ 0.05	$ 1.46	$ 0.54	$ 3.66		$ 0.73		$ 4.75
Stock options outstanding	131,000				131,000				131,000		131,000		131,000
Weighted average exercise price for stock options	$ 30.00				$ 30.00				$ 30.00		$ 30.00		$ 30.00

[1] For the years ended December 31, 2011, 2010 and 2009, the Company had an aggregate of 131,000 stock options outstanding with a weighted average exercise price of $30.00 that were not included in the calculation of EPS as their inclusion would have been anti-dilutive. These equity instruments may have a dilutive impact on future EPS.