Financial Instruments - Accumulated Unrealized Losses on Marketable Debt Securities in Continuous Loss Position (Detail) $ in Thousands	Mar. 31, 2024 USD ($) security	Dec. 31, 2023 USD ($)
Investments, Debt and Equity Securities [Abstract]
Number of securities in an unrealized loss position | security	15
Schedule Of Available For Sale Securities [Line Items]
Less than 12 months, Estimated Fair Value	$ 35,819	$ 930
Less than 12 months, Gross Unrealized Losses	(13)	(49)
More than 12 months, Estimated Fair Value	0	0
More than 12 months, Gross Unrealized Losses	0	0
U.S. Treasury securities
Schedule Of Available For Sale Securities [Line Items]
Less than 12 months, Estimated Fair Value	20,832
Less than 12 months, Gross Unrealized Losses	(4)
More than 12 months, Estimated Fair Value	0
More than 12 months, Gross Unrealized Losses	0
U.S. Government Agency securities
Schedule Of Available For Sale Securities [Line Items]
Less than 12 months, Estimated Fair Value	14,987
Less than 12 months, Gross Unrealized Losses	(9)
More than 12 months, Estimated Fair Value	0
More than 12 months, Gross Unrealized Losses	$ 0
Mutual funds
Schedule Of Available For Sale Securities [Line Items]
Less than 12 months, Estimated Fair Value		39
Less than 12 months, Gross Unrealized Losses		(1)
More than 12 months, Estimated Fair Value		0
More than 12 months, Gross Unrealized Losses		0
Foreign bonds
Schedule Of Available For Sale Securities [Line Items]
Less than 12 months, Estimated Fair Value		891
Less than 12 months, Gross Unrealized Losses		(48)
More than 12 months, Estimated Fair Value		0
More than 12 months, Gross Unrealized Losses		$ 0