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, 2016	Dec. 31, 2015	Dec. 31, 2014
Current expense (benefit):
Federal									$ 1,933	$ (17)	$ 1,316
State									492	747	768
Foreign									3,802	3,218	2,644
Total current expense									6,227	3,948	4,728
Deferred expense (benefit):
Federal									(144)	3,250	4,078
State									(195)	294	(119)
Foreign									(623)	(94)	(89)
Total deferred (benefit) expense									(962)	3,450	3,870
Total income tax expense	$ 2,116	$ (978)	$ 2,572	$ 1,555	$ 145	$ 1,842	$ 3,122	$ 2,289	$ 5,265	$ 7,398	$ 8,598