Short-Term and Other Borrowings - Summary of Federal Funds Purchased, Securities Sold Under Agreements to Repurchase and Other Short-term Borrowings (Detail)	3 Months Ended
	Mar. 31, 2020 USD ($)
Federal Funds Purchased [Member]
Short-term Debt [Line Items]
Maximum indebtedness	$ 37,000,000
Average balance	$ 610,000
Average rate paid	1.32%
Short Term Borrowings, FHLB advances [Member]
Short-term Debt [Line Items]
Maximum indebtedness	$ 102,700,000
Average balance	$ 32,749,000
Average rate paid	1.65%