Fair Value Measurements - Summary of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis and Level of the Fair Value Hierarchy (Detail) - Fair value on a recurring basis [Member] - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Investments [Member]
Investments:
Total investments	$ 789,745	$ 470,500
Investments [Member] \| U.S. treasury bills [Member]
Investments:
Total investments	704,578	401,184
Investments [Member] \| U.S. agency securities [Member]
Investments:
Total investments	85,167	69,316
Investments [Member] \| Level 2 [Member]
Investments:
Total investments	789,745	470,500
Investments [Member] \| Level 2 [Member] \| U.S. treasury bills [Member]
Investments:
Total investments	704,578	401,184
Investments [Member] \| Level 2 [Member] \| U.S. agency securities [Member]
Investments:
Total investments	85,167	69,316
Cash equivalents [Member]
Cash equivalents:
Assets, fair value	118,397	80,313
Cash equivalents [Member] \| Money market funds [Member]
Cash equivalents:
Assets, fair value	118,397	80,313
Cash equivalents [Member] \| Level 1 [Member]
Cash equivalents:
Assets, fair value	118,397	80,313
Cash equivalents [Member] \| Level 1 [Member] \| Money market funds [Member]
Cash equivalents:
Assets, fair value	$ 118,397	$ 80,313

Fair Value Measurements - Summary of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis and Level of the Fair Value Hierarchy (Detail) - Fair value on a recurring basis [Member] - USD ($)
$ in Thousands

Jun. 30, 2026

Dec. 31, 2025

Investments:

Total investments

$ 789,745

$ 470,500

Investments [Member] | U.S. treasury bills [Member]

Investments:

Total investments

704,578

401,184

Investments [Member] | U.S. agency securities [Member]