Fair Value Measurements - Debt Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	$ 676,446	$ 561,100
Gross Unrealized Gains	120	0
Gross Unrealized Losses	1	0
Estimated Fair Value	676,565	561,100
U.S. Government
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	676,446	561,100
Gross Unrealized Gains	120	0
Gross Unrealized Losses	1	0
Estimated Fair Value	$ 676,565	$ 561,100