Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period			$ 179,189
Current period other comprehensive income (loss) before reclassifications	$ (250)	$ 268	(244)	$ 371
Reclassification of amounts to earnings	(42)	41	(58)	109
Net other comprehensive income (loss) during period	(292)	309	(302)	480
Balance at end of period	185,590		185,590
Unrealized Loss on Available-for-Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(101)	(27)	(64)	(8)
Current period other comprehensive income (loss) before reclassifications	34	(9)	(3)	(28)
Reclassification of amounts to earnings	0	0	0	0
Net other comprehensive income (loss) during period	34	(9)	(3)	(28)
Balance at end of period	(67)	(36)	(67)	(36)
Gain on Derivative Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	360	95	216	(24)
Current period other comprehensive income (loss) before reclassifications	54	(53)	214	(2)
Reclassification of amounts to earnings	(42)	41	(58)	109
Net other comprehensive income (loss) during period	12	(12)	156	107
Balance at end of period	372	83	372	83
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(528)	(1,114)	(411)	(1,185)
Current period other comprehensive income (loss) before reclassifications	(338)	330	(455)	401
Reclassification of amounts to earnings	0	0	0	0
Net other comprehensive income (loss) during period	(338)	330	(455)	401
Balance at end of period	(866)	(784)	(866)	(784)
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(269)	(1,046)	(259)	(1,217)
Balance at end of period	$ (561)	$ (737)	$ (561)	$ (737)