Investment Securities - Proceeds from Sale, Gross Gains (Losses) Realized on Sales, Maturities and Other-Than-Temporary Impairment Charges Related to Securities Available for Sale (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Gain (Loss) on Securities [Line Items]
Proceeds from sale	$ 0	$ 0	$ 0
Debt Securities, Realized Gain (Loss), Total	2	16	70
Calls And Maturities [Member]
Gain (Loss) on Securities [Line Items]
Gross gains	2	16	70
Gross Losses	0	0	0
Debt Securities, Realized Gain (Loss), Total	2	16	70
Sales [Member]
Gain (Loss) on Securities [Line Items]
Gross gains	0	0	0
Gross Losses	0	0	0
Debt Securities, Realized Gain (Loss), Total	$ 0	$ 0	$ 0