Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Earnings Per Share [Abstract]
Income from continuing operations	$ 42,155		$ 27,606
Loss from discontinued operations, net of tax (Note 12)	(6,556)		(4,431)
Net income	35,599		23,175
Distributed income from continuing operations to common shares	5,454		0
Distributed income from continuing operations to participating shares	148		0
Total distributed income from continuing operations	5,602		0
Undistributed income from continuing operations to common shares	35,321		26,860
Undistributed income from continuing operations to participating shares	1,232		746
Total undistributed income from continuing operations	36,553		27,606
Income from continuing operations to common shares - basic	40,775		26,860
Undistributed income from continuing operations reallocated to participating shares	(1,231)		(727)
Income from continuing operations to common shares - diluted	$ 40,776		$ 26,879
Weighted Average Number of Shares Outstanding, Basic	18,269		23,944
Dilutive effect of share-based payment awards	17		112
Dilutive effect of convertible debt	0		519
Weighted Average Number of Shares Outstanding, Diluted	18,286	[1]	24,575	[1]
Continuing operations (in dollars per share)	$ 2.23		$ 1.12
Discontinued operations (in dollars per share)	$ (0.36)		$ (0.18)
Basic earnings per share	$ 1.87		$ 0.94
Continuing operations (in dollars per share)	$ 2.23		$ 1.09
Discontinued operations (in dollars per share)	$ (0.36)		$ (0.18)
Diluted earnings per common share	$ 1.87		$ 0.91
Stock options and share-based awards not included in diluted EPS calculation because their effect would have be antidilutive	3		156

[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.