Balance Sheet Items - Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance, beginning of period	$ 254	$ 0	$ 146	$ 0
Add: provision	0	0	119	0
Less: deduction and other adjustments	(5)	0	(16)	0
Balance, end of period	$ 249	$ 0	$ 249	$ 0