Income Taxes (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current tax expense (benefit)
Federal	$ 14,275	$ 96,273	$ 84,281
State	5,821	2,835	12,145
Foreign	7,515	4,708	(3,366)
Total current	27,611	103,816	93,060
Deferred tax (benefit) expense
Federal	2,357	(137,803)	44,225
State	551	407	164
Total deferred	2,908	(137,396)	44,389
Total income tax (benefit) provision	$ 30,519	$ (33,580)	$ 137,449
Percent of pretax (loss) income
Federal taxes (as a percent)	35.00%	35.00%	35.00%
State and local income taxes (as a percent)	1.60%	1.50%	1.20%
Permanent differences (as a percent)	(20.90%)	(16.80%)	5.90%
Foreign (as a percent)	(2.20%)	(0.60%)	0.20%
Valuation allowance (as a percent)	(31.10%)	(14.00%)	0.00%
Other miscellaneous items (as a percent)	(2.30%)	0.30%	(0.10%)
Actual effective income tax rate (as a percent)	(19.90%)	5.40%	42.20%
Amount based upon pretax (loss) income
Federal taxes	$ (53,656)	$ (219,232)	$ 113,759
State and local income taxes	(2,470)	(9,163)	3,918
Permanent differences	32,019	104,592	19,193
Foreign	3,337	3,685	886
Valuation allowance	47,703	92,242
Other miscellaneous items	3,586	(5,704)	(307)
Total income tax (benefit) provision	30,519	(33,580)	137,449
Reconciliation of liability for unrecognized tax benefits
Balance at the beginning of the period	21,564	20,393
Additions based on current year positions	1,142	2,026
Additions based on prior year positions	4,038	5,537
Payments made on account	(12,132)
Decreases due to settlements and/or reduction in reserve	(5,097)	(4,570)
Currency translation adjustments	(2,480)	(1,822)
Balance at the end of the period	$ 7,035	$ 21,564	$ 20,393