Fair Value Measurements - Level of the fair value hierarchy (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Fair Value Measurements
Total fair value of financial assets	$ 1,452,894	$ 1,441,663
LEVEL 1
Fair Value Measurements
Total fair value of financial assets	985,681	1,180,481
LEVEL 2
Fair Value Measurements
Total fair value of financial assets	467,213	261,182
Recurring | Money market funds
Fair Value Measurements
Total fair value of financial assets	310,558	795,089
Recurring | U.S. government bonds
Fair Value Measurements
Total fair value of financial assets	675,123	385,392
Recurring | U.S. government agency bonds
Fair Value Measurements
Total fair value of financial assets	34,599	24,941
Recurring | Corporate debt securities
Fair Value Measurements
Total fair value of financial assets	432,614	236,241
Recurring | LEVEL 1 | Money market funds
Fair Value Measurements
Total fair value of financial assets	310,558	795,089
Recurring | LEVEL 1 | U.S. government bonds
Fair Value Measurements
Total fair value of financial assets	675,123	385,392
Recurring | LEVEL 2 | U.S. government agency bonds
Fair Value Measurements
Total fair value of financial assets	34,599	24,941
Recurring | LEVEL 2 | Corporate debt securities
Fair Value Measurements
Total fair value of financial assets	$ 432,614	$ 236,241