Stock-Based Compensation - Schedule of AOCI (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
AOCI Attributable to Parent [Roll Forward]
Beginning balance		$ 99,515	$ 105,665
Other comprehensive income, net of tax	[1]	1,088	2,467
Ending balance		95,598	106,834
Foreign Currency Translation
AOCI Attributable to Parent [Roll Forward]
Beginning balance		(14,720)	(11,247)
Other comprehensive income before reclassifications		1,080	2,444
Amounts reclassified from AOCI to Other income (expense), net		0	0
Other comprehensive income, net of tax		1,080	2,444
Ending balance		(13,640)	(8,803)
Unrealized Gain (Loss) on Available for Sale Marketable Securities
AOCI Attributable to Parent [Roll Forward]
Beginning balance		0	(1)
Other comprehensive income before reclassifications		0	1
Amounts reclassified from AOCI to Other income (expense), net		0	0
Other comprehensive income, net of tax		0	1
Ending balance		0	0
Interest Rate Swaps
AOCI Attributable to Parent [Roll Forward]
Beginning balance		(11)	(69)
Other comprehensive income before reclassifications		0	7
Amounts reclassified from AOCI to Other income (expense), net		8	15
Other comprehensive income, net of tax		8	22
Ending balance		(3)	(47)
Total Accumulated Other Comprehensive Loss
AOCI Attributable to Parent [Roll Forward]
Beginning balance		(14,731)	(11,317)
Other comprehensive income before reclassifications		1,080	2,452
Amounts reclassified from AOCI to Other income (expense), net		8	15
Other comprehensive income, net of tax		1,088	2,467
Ending balance		$ (13,643)	$ (8,850)

[1] Tax impact was nominal for all periods.