Cash, Cash Equivalents and Investments - Securities in Continuous Loss Position (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Adjusted Cost	$ 90,158	$ 111,565
Gross Unrealized Loss	(226)	(23)
Fair Value	89,932	111,542
U.S. government securities
Debt Securities, Available-for-sale [Line Items]
Adjusted Cost	48,658	90,120
Gross Unrealized Loss	(160)	(14)
Fair Value	48,498	90,106
Corporate bonds and commercial paper
Debt Securities, Available-for-sale [Line Items]
Adjusted Cost	41,500	21,445
Gross Unrealized Loss	(66)	(9)
Fair Value	$ 41,434	$ 21,436