Income Taxes - Schedule of Income Tax Amounts were Recorded in Shareholder's Equity as Elements of Other Comprehensive Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Securities and defined benefit pension plan unrecognized items	$ 12,369	$ (82,295)	$ (11,322)