Fair Value Measurements - Debt Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	$ 78,185	$ 561,100
Gross Unrealized Gains	65	0
Gross Unrealized Losses	0	0
Estimated Fair Value	78,250	561,100
U.S. Government
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	78,185	561,100
Gross Unrealized Gains	65	0
Gross Unrealized Losses	0	0
Estimated Fair Value	$ 78,250	$ 561,100