Fair Value Measurements - Schedule of Fair Value Assets and Liabilities Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Assets:
Marketable securities	$ 1,127,743	$ 1,110,207
Fair Value Recurring [Member]
Assets:
Cash equivalents	147,708	251,567
Total assets	1,275,451	1,361,774
Fair Value Recurring [Member] | Related Party Revenue Share Liability [Member]
Liabilities:
Total liabilities	75,730	73,160
Fair Value Recurring [Member] | Commercial Paper [Member]
Assets:
Marketable securities	123,965	107,884
Fair Value Recurring [Member] | Corporate bonds [Member]
Assets:
Marketable securities	790,927	774,506
Fair Value Recurring [Member] | Government and agency securities [Member]
Assets:
Marketable securities	193,202	207,990
Fair Value Recurring [Member] | U.S. treasury bills [Member]
Assets:
Marketable securities	19,649	19,827
Fair Value Recurring [Member] | Fair value, inputs, level 1 [Member]
Assets:
Cash equivalents	147,708	251,567
Total assets	147,708	251,567
Fair Value Recurring [Member] | Fair value, inputs, level 2 [Member]
Assets:
Total assets	1,127,743	1,110,207
Fair Value Recurring [Member] | Fair value, inputs, level 2 [Member] | Commercial Paper [Member]
Assets:
Marketable securities	123,965	107,884
Fair Value Recurring [Member] | Fair value, inputs, level 2 [Member] | Corporate bonds [Member]
Assets:
Marketable securities	790,927	774,506
Fair Value Recurring [Member] | Fair value, inputs, level 2 [Member] | Government and agency securities [Member]
Assets:
Marketable securities	193,202	207,990
Fair Value Recurring [Member] | Fair value, inputs, level 2 [Member] | U.S. treasury bills [Member]
Assets:
Marketable securities	19,649	19,827
Fair Value Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Related Party Revenue Share Liability [Member]
Liabilities:
Total liabilities	$ 75,730	$ 73,160