Divestitures (Schedule of Results of Discontinued Operations) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Discontinued Operations and Disposal Groups [Abstract]
Disposal Group, Including Discontinued Operation, Inventory, Current	$ 33,730					$ 33,730
Disposal Group, Including Discontinued Operation, Assets, Current	2,060					2,060
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment	35,560					35,560
Disposal Group, Including Discontinued Operation, Assets, Noncurrent	190					190
Disposal Group, Including Discontinued Operation, Accounts Payable and Accrued Liabilities	10,599					10,599
Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent	38,340					38,340
Total Revenues						219,002	390,912
Income from discontinued operations before income taxes						32,167	75,418
Gain on sale					27,512	120,321	0
Less: income tax expense						49,092	20,190
Income from discontinued operations, including gain on sale - net of tax	$ 1,580	$ 79,404	$ 8,145	$ 14,267	$ 0	$ 103,396	$ 55,228
Basic earnings per common share from discontinued operations						$ 0.49	$ 0.26
Diluted earnings per common share from discontinued operations						$ 0.49	$ 0.26