Income Taxes (Details 2) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Expense (Benefit), Continuing Operations, by Jurisdiction [Abstract]
Foreign									$ 7,058	$ 2,821	$ 4,301
U.S. federal									0	0	0
U.S. state									383	0	32
Current income tax provision (benefit)									7,441	2,821	4,333
Foreign									5,318	4,071	4,747
U.S. federal									(15,379)	5,142	21,865
U.S. state									232	(766)	2,585
Deferred income tax provision (benefit)									(9,829)	8,447	29,197
Provision (benefit) for income taxes	$ 31,141	$ (37,249)	$ 3,625	$ 95	$ 16,119	$ 11,898	$ 4,658	$ (21,407)	$ (2,388)	$ 11,268	$ 33,530