Fair Value of Assets and Liabilities - Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended	12 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net change in unrealized gains (losses) on investments, net of tax	$ 102	$ (150)	$ (906)	$ 506		$ (300)
Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net change in unrealized gains (losses) on investments, net of tax					$ (100)
AOCI Attributable to Parent [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net change in unrealized gains (losses) on investments, net of tax	$ 102	$ (150)	$ (906)	$ 506