Balance Sheet Components - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	$ 679,617	$ 554,341	$ 458,836
Other comprehensive income (loss) before reclassifications	1,976	(3,543)
Amounts reclassified from other comprehensive income (loss), net of tax	(568)	(1,198)
Other comprehensive income (loss)	1,408	(4,741)	3,406
Balance	845,254	679,617	554,341
Foreign currency translation adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	(11,274)	(6,954)
Other comprehensive income (loss) before reclassifications	1,828	(4,320)
Amounts reclassified from other comprehensive income (loss), net of tax	0	0
Other comprehensive income (loss)	1,828	(4,320)
Balance	(9,446)	(11,274)	(6,954)
Unrealized gain (loss) on interest rate swap hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	420	841
Other comprehensive income (loss) before reclassifications	148	777
Amounts reclassified from other comprehensive income (loss), net of tax	(568)	(1,198)
Other comprehensive income (loss)	(420)	(421)
Balance	0	420	841
Accumulated other comprehensive income (loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	(10,854)	(6,113)	(9,519)
Other comprehensive income (loss)	1,408	(4,741)	3,406
Balance	$ (9,446)	$ (10,854)	$ (6,113)