Fair Value Measurements - Fair value to amortized cost (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Fair Value Measurements
AMORTIZED COST	$ 778,172	$ 874,422
UNREALIZED LOSSES	(184)	(427)
UNREALIZED GAINS	546	1,341
FAIR VALUE	778,534	875,336
Money market funds
Fair Value Measurements
AMORTIZED COST	139,062	161,328
FAIR VALUE	139,062	161,328
U.S. government bonds
Fair Value Measurements
AMORTIZED COST	253,319	262,316
UNREALIZED LOSSES	(20)	(48)
UNREALIZED GAINS	438	747
FAIR VALUE	253,737	263,015
U.S. government agency bonds
Fair Value Measurements
AMORTIZED COST	37,565	46,890
UNREALIZED LOSSES	(1)	(11)
UNREALIZED GAINS	16	78
FAIR VALUE	37,580	46,957
Corporate debt securities
Fair Value Measurements
AMORTIZED COST	348,226	403,888
UNREALIZED LOSSES	(163)	(368)
UNREALIZED GAINS	92	516
FAIR VALUE	$ 348,155	$ 404,036

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost excluding accrued interest, before allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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