Balance Sheet Components - Cash and Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Cash and Cash Equivalents
Cash	$ 10,984	$ 17,065
Cash equivalents	36,380	152,974
Total cash and cash equivalents	47,364	170,039
Cash, Cash Equivalents and Restricted Cash
Cash and cash equivalents	47,364	170,039
Restricted cash, current portion	12,105	12,105
Restricted cash, net of current portion	460	460
Total restricted cash	12,565	12,565
Total cash and cash equivalents, and restricted cash	$ 59,929	$ 182,604	$ 46,096	$ 123,697