Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income [Abstract]
Accumulated other comprehensive income	$ 325	$ 67	$ 325	$ 67	$ 309	$ 307	$ (122)	$ (260)
Foreign currency translation adjustments	16	189	18	327
Translation Adjustment Functional to Reporting Currency, Tax Benefit (Expense)	0	0	0	0
Total other comprehensive income, net of tax	$ 16	$ 189	$ 18	$ 327

Amount after tax, before reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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