Basis of Presentation and Principles of Consolidation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Change to Two-Class Method [Line Items]
Income from continuing operations used in basic per share calculation		$ (47,472)	$ 23,016	$ (5,465)	$ 49,880
Income from continuing operations used in diluted per share calculation		$ (47,472)	$ 23,036	$ (5,465)	$ 49,918
Weighted average shares used in basic per share calculation		17,848	19,541	18,057	21,730
Weighted average shares used in diluted per share calculation	[1]	17,848	20,048	18,057	22,298
Basic earnings per common share from continuing operations		$ (2.66)	$ 1.18	$ (0.30)	$ 2.30
Diluted earnings per common share from continuing operations		$ (2.66)	$ 1.15	$ (0.30)	$ 2.24
As Reported Under the Treasury Stock Method
Change to Two-Class Method [Line Items]
Income from continuing operations used in basic per share calculation			$ 23,833		$ 51,439
Income from continuing operations used in diluted per share calculation			$ 23,833		$ 51,439
Weighted average shares used in basic per share calculation			19,541		21,730
Weighted average shares used in diluted per share calculation			20,181		22,488
Basic earnings per common share from continuing operations			$ 1.22		$ 2.37
Diluted earnings per common share from continuing operations			$ 1.18		$ 2.29
Amount Allocated to Participating Securities
Change to Two-Class Method [Line Items]
Income from continuing operations used in basic per share calculation			$ (817)		$ (1,559)
Income from continuing operations used in diluted per share calculation			$ (797)		$ (1,521)
Weighted average shares used in basic per share calculation			0		0
Weighted average shares used in diluted per share calculation			(133)		(190)
Basic earnings per common share from continuing operations			$ (0.04)		$ (0.07)
Diluted earnings per common share from continuing operations			$ (0.03)		$ (0.05)

[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.