Balance Sheet Details (Schedule of Accumulated Other Comprehensive Income) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Accumulated Other Comprehensive Income [Roll Forward]
Balance as of December 31, 2018	$ 90,591
Balance as of March 31, 2019	75,937
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income [Roll Forward]
Balance as of December 31, 2018	(296)
Other comprehensive income before reclassification	(461)
Amounts reclassified from accumulated other comprehensive income	0
Net other comprehensive income for the three months ended March 31, 2019	(461)
Balance as of March 31, 2019	(757)
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income [Roll Forward]
Balance as of December 31, 2018	394
Other comprehensive income before reclassification	(461)
Amounts reclassified from accumulated other comprehensive income	0
Net other comprehensive income for the three months ended March 31, 2019	(461)
Balance as of March 31, 2019	(67)
Defined Benefit Plans
Accumulated Other Comprehensive Income [Roll Forward]
Balance as of December 31, 2018	(690)
Other comprehensive income before reclassification	0
Amounts reclassified from accumulated other comprehensive income	0
Net other comprehensive income for the three months ended March 31, 2019	0
Balance as of March 31, 2019	$ (690)