Cash, Cash Equivalents, Restricted Cash and Investments - Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Marketable Securities [Line Items]
Amortized Cost	$ 338,041	$ 389,646
Unrealized Gains	3	0
Unrealized Losses	(144)	(256)
Estimated Fair Value	337,900	389,390
Total cash, cash equivalents, restricted cash and investments	338,491
Cash, cash equivalents and restricted cash
Marketable Securities [Line Items]
Amortized Cost	46,397	94,172
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	46,397	94,172
U.S. agency securities
Marketable Securities [Line Items]
Amortized Cost		4,951
Unrealized Gains		0
Unrealized Losses		(3)
Estimated Fair Value		4,948
Corporate bonds
Marketable Securities [Line Items]
Amortized Cost	31,820	104,174
Unrealized Gains	0	0
Unrealized Losses	(15)	(94)
Estimated Fair Value	31,805	104,080
Commercial paper
Marketable Securities [Line Items]
Amortized Cost	93,960	125,255
Unrealized Gains	0	0
Unrealized Losses	(44)	(68)
Estimated Fair Value	93,916	125,187
Treasury bills
Marketable Securities [Line Items]
Amortized Cost	80,210	12,290
Unrealized Gains	3	0
Unrealized Losses	0	(8)
Estimated Fair Value	80,213	12,282
Treasury bonds
Marketable Securities [Line Items]
Amortized Cost	85,654	42,301
Unrealized Gains	0	0
Unrealized Losses	(85)	(81)
Estimated Fair Value	85,569	42,220
Yankee bonds
Marketable Securities [Line Items]
Amortized Cost	0	6,503
Unrealized Gains	0	0
Unrealized Losses	0	(2)
Estimated Fair Value	0	$ 6,501
Long-term corporate bond
Marketable Securities [Line Items]
Amortized Cost	592
Unrealized Gains	0
Unrealized Losses	(1)
Estimated Fair Value	$ 591