Fair Value Measurements - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Transfers between Level 1, Level 2 and Level 3 securities	$ 0	$ 0
Proceeds from the sales and maturities of securities available-for-sale	29,500,000	0	$ 19,400,000
Purchases of investments	78,600,000	50,100,000	$ 25,000,000
Realized loss	1,500,000
Realized gain		800,000
Net unrealized gain/loss	3,600,000	(1,700,000)
Credit losses on available-for-sale securities	$ 0	$ 0