Income Taxes - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal									$ 600	$ 4,695	$ 1,866
State									0	2,098	299
Foreign									(4,817)	(2,743)	(1,847)
Deferred:
Federal									40,634	26,074	2,473
State									1,340	1,301	103
Foreign									(2,894)	1,795	(506)
Income tax benefit	$ 14,460	$ 3,610	$ (370)	$ 15,520	$ 7,110	$ 7,780	$ (8,410)	$ (4,092)	$ 34,863	$ 33,220	$ 2,388