Summary of Significant Accounting Policies (Change To Two Class Method) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Change To Two Class Method [Line Items]
Income from continuing operations used in basic per share calculation		$ 48,117	$ 120,748	$ 217,215
Income from continuing operations used in diluted per share calculation		$ 48,118	$ 120,806	$ 217,394
Weighted average shares used for basic EPS (in shares)		17,467	20,192	27,216
Weighted average shares used for diluted EPS (in shares)	[1]	17,487	20,503	28,169
Basic earnings per common share from continuing operations (in usd per share)		$ 2.75	$ 5.98	$ 7.98
Diluted earnings per common share from continuing operations (in usd per share)		$ 2.75	$ 5.89	$ 7.72
Scenario, Previously Reported [Member]
Change To Two Class Method [Line Items]
Income from continuing operations used in basic per share calculation			$ 124,677	$ 222,688
Income from continuing operations used in diluted per share calculation			$ 124,677	$ 222,688
Weighted average shares used for basic EPS (in shares)			20,192	27,216
Weighted average shares used for diluted EPS (in shares)			20,699	28,381
Basic earnings per common share from continuing operations (in usd per share)			$ 6.17	$ 8.18
Diluted earnings per common share from continuing operations (in usd per share)			$ 6.02	$ 7.85
Restatement Adjustment [Member]
Change To Two Class Method [Line Items]
Income from continuing operations used in basic per share calculation			$ (3,929)	$ (5,473)
Income from continuing operations used in diluted per share calculation			$ (3,871)	$ (5,294)
Weighted average shares used for basic EPS (in shares)			0	0
Weighted average shares used for diluted EPS (in shares)			(196)	(212)
Basic earnings per common share from continuing operations (in usd per share)			$ (0.19)	$ (0.20)
Diluted earnings per common share from continuing operations (in usd per share)			$ (0.13)	$ (0.13)

[1] Participating securities were included in the calculation of diluted earnings per share using the two-class method, as this calculation was more dilutive than the calculation using the treasury stock method.