Significant Accounting Policies - Estimated Fair Value of Assets and Liability (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Asset:
Asset, fair value	$ 244,647	$ 235,380
Money Market Fund
Asset:
Asset, fair value	73,927	99,226
Agency Securities
Asset:
Asset, fair value		8,912
Repo Securities
Asset:
Asset, fair value	5,000	3,250
U.S. Treasury Securities
Asset:
Asset, fair value	165,720	123,992
Level 1
Asset:
Asset, fair value	239,647	223,218
Level 1 | Money Market Fund
Asset:
Asset, fair value	73,927	99,226
Level 1 | U.S. Treasury Securities
Asset:
Asset, fair value	165,720	123,992
Level 2
Asset:
Asset, fair value	5,000	12,162
Level 2 | Agency Securities
Asset:
Asset, fair value		8,912
Level 2 | Repo Securities
Asset:
Asset, fair value	$ 5,000	$ 3,250