Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income before income taxes:
Domestic	$ 2,901	$ 13,988	$ 18,656
Foreign	16,788	16,046	10,967
Total income before income taxes	19,689	30,034	29,623
Current:
Federal	3,210	5,511	6,802
State and local	256	1,152	1,418
Foreign	3,645	4,885	3,710
Total current	7,111	11,548	11,930
Deferred:
Federal	(241)	(1,039)	(198)
State and local	(176)	56	23
Foreign	104	(778)	(921)
Total deferred	(313)	(1,761)	(1,096)
Total income tax expense	$ 6,798	$ 9,787	$ 10,834