Balance Sheet Details (Schedule of Accumulated Other Comprehensive Income) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018 USD ($)
Accumulated Other Comprehensive Income [Roll Forward]
Balance as of December 31, 2017	$ 106,101
Balance as of June 30, 2018	90,654
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income [Roll Forward]
Balance as of December 31, 2017	12,076
Other comprehensive income before reclassification	(1,967)
Amounts reclassified from accumulated other comprehensive income	38
Net other comprehensive income for the six months ended June 30, 2018	(1,929)
Balance as of June 30, 2018	10,147
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income [Roll Forward]
Balance as of December 31, 2017	12,957
Other comprehensive income before reclassification	(1,967)
Amounts reclassified from accumulated other comprehensive income	0
Net other comprehensive income for the six months ended June 30, 2018	(1,967)
Balance as of June 30, 2018	10,990
Defined Benefit Pension Plan
Accumulated Other Comprehensive Income [Roll Forward]
Balance as of December 31, 2017	(881)
Other comprehensive income before reclassification	0
Amounts reclassified from accumulated other comprehensive income	38
Net other comprehensive income for the six months ended June 30, 2018	38
Balance as of June 30, 2018	$ (843)