Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income [Abstract]
Accumulated other comprehensive income	$ 430	$ 269	$ 430	$ 269	$ 325	$ 307	$ 67	$ (260)
Foreign currency translation adjustments	105	202	123	529
Translation Adjustment Functional to Reporting Currency, Tax Benefit (Expense)	0	0	0	0
Total other comprehensive income, net of tax	$ 105	$ 202	$ 123	$ 529