Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Income (loss) from continuing operations		$ 40,548	$ (47,351)	$ 78,999	$ (5,196)
Income (loss) from discontinued operations, net of tax		0	1,735	0	(4,821)
Net income (loss)		40,548	(45,616)	78,999	(10,017)
Dividends and undistributed income allocated to participating shares		(1,933)	(121)	(3,334)	(269)
Income from continuing operations to common shares - basic		38,615	(47,472)	75,665	(5,465)
Effect of reallocating undistributed income from continuing operations to participating shares		11	0	16	0
Income from continuing operations to common shares - diluted		$ 38,626	$ (47,472)	$ 75,681	$ (5,465)
Weighted average common shares - basic (in shares)		16,149	17,848	16,122	18,057
Dilutive effect of share-based payment awards (in shares)		95	0	94	0
Weighted average common shares - diluted (in shares)	[1]	16,244	17,848	16,216	18,057
Basic earnings (loss) per common share:
Continuing operations (in usd per share)		$ 2.39	$ (2.66)	$ 4.69	$ (0.30)
Discontinued operations (in usd per share)		0.00	0.10	0.00	(0.27)
Basic earnings (loss) per common share (in usd per share)		2.39	(2.56)	4.69	(0.57)
Diluted earnings (loss) per common share:
Continuing operations (in usd per share)		2.38	(2.66)	4.67	(0.30)
Discontinued operations (in usd per share)		0.00	0.10	0.00	(0.27)
Diluted earnings (loss) per common share (in usd per share)		$ 2.38	$ (2.56)	$ 4.67	$ (0.57)
Stock options and share-based awards not included in diluted EPS calculation because their effect would have be antidilutive (in shares)		248	14	121	16

[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.