Balance Sheet Components - Valuation And Qualifying Accounts (Details) - ALLOWANCE FOR DOUBTFUL ACCOUNTS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance January 1	$ 6,347	$ 6,709	$ 7,764
Charged to costs and expenses, net of recoveries	34	1,181	290
Utilization	(525)	(1,443)	(1,396)
Currency translation and other	235	(100)	51
Ending balance December 31	$ 6,091	$ 6,347	$ 6,709