Fair Value Measurements - Level of the fair value hierarchy (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Fair Value Measurements
Total fair value of financial assets	$ 1,337,052	$ 1,441,663
LEVEL 1
Fair Value Measurements
Total fair value of financial assets	905,662	1,180,481
LEVEL 2
Fair Value Measurements
Total fair value of financial assets	431,390	261,182
Recurring \| Money market funds
Fair Value Measurements
Total fair value of financial assets	267,032	795,089
Recurring \| U.S. government bonds
Fair Value Measurements
Total fair value of financial assets	638,630	385,392
Recurring \| U.S. government agency bonds
Fair Value Measurements
Total fair value of financial assets	34,647	24,941
Recurring \| Corporate debt securities
Fair Value Measurements
Total fair value of financial assets	396,743	236,241
Recurring \| LEVEL 1 \| Money market funds
Fair Value Measurements
Total fair value of financial assets	267,032	795,089
Recurring \| LEVEL 1 \| U.S. government bonds
Fair Value Measurements
Total fair value of financial assets	638,630	385,392
Recurring \| LEVEL 2 \| U.S. government agency bonds
Fair Value Measurements
Total fair value of financial assets	34,647	24,941
Recurring \| LEVEL 2 \| Corporate debt securities
Fair Value Measurements
Total fair value of financial assets	$ 396,743	$ 236,241