Financial Instruments (Details) $ in Thousands	Mar. 31, 2024 USD ($) position	Dec. 31, 2023 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	$ 884,826	$ 881,708
Gross Unrealized Gain	1	14
Gross Unrealized Loss	(1,889)	(2,745)
Estimated Fair Value	882,938	878,977
Cash, cash equivalents and restricted cash	813,817	642,095	$ 403,154	$ 466,091
Short-term investments	$ 69,121	236,882
Number of investments, unrealized loss position | position	14
Fair value	$ 65,687
Unrealized loss	(1,889)
Amortized Cost
Less than or equal to one year	52,960
Greater than one year but less than five years	18,049
Total	71,009
Fair Value
Less than or equal to one year	52,032
Greater than one year but less than five years	17,089
Total	69,121
Cash, cash equivalents, and restricted cash
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	813,817	642,095
Estimated Fair Value	813,817	642,095
U.S. Treasury securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	34,996	201,522
Gross Unrealized Gain		14
Gross Unrealized Loss	(531)	(1,118)
Estimated Fair Value	34,465	200,418
Fair value	34,465
Unrealized loss	(531)
Municipal securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	36,013	38,091
Gross Unrealized Gain	1
Gross Unrealized Loss	(1,358)	(1,627)
Estimated Fair Value	34,656	$ 36,464
Fair value	31,222
Unrealized loss	(1,358)
Available-for-sale securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Fair value	$ 0