Income Taxes - Provision for Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current taxes:
U.S. federal									$ 2,868	$ 1,868	$ 8,792
State and local									410	1,937	1,181
Foreign									4,982	9,968	1,786
Total current tax expense									8,260	13,773	11,759
Deferred taxes:
U.S. federal									293	202	14,626
State and local									(534)	50	795
Foreign									(574)	5,183	(827)
Total deferred tax (benefit) expense									(815)	5,435	14,594
Total tax expense	$ 11,900	$ 4,500	$ (4,300)	$ (4,700)	$ 4,700	$ 3,800	$ 3,300	$ 7,400	$ 7,445	$ 19,208	$ 26,353