Short-term Borrowings - Interest Expense on Short-Term Borrowings (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Interest On Short Term Borrowings [Line Items]
Total interest on short-term borrowings	$ 99	$ 704	$ 8,298
Federal funds purchased
Interest On Short Term Borrowings [Line Items]
Total interest on short-term borrowings	0	44	204
Borrowings from FHLB
Interest On Short Term Borrowings [Line Items]
Total interest on short-term borrowings	0	434	7,313
Securities sold under agreements to repurchase
Interest On Short Term Borrowings [Line Items]
Total interest on short-term borrowings	$ 99	$ 226	$ 781