Federal Funds Purchased and Securities Sold Under Agreements to Repurchase - Schedule of Remaining Contractual Maturity in Repurchase Agreements (Detail) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Assets Sold under Agreements to Repurchase [Line Items]
Federal funds purchased	$ 21,000	$ 22,573
Repurchase agreements, Remaining contractual maturity of the agreements	30,600	31,600
Total	51,567	54,206
Overnight & Continuous [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Federal funds purchased	21,000	22,573
Total	22,599	23,688
Greater Than 90 Days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Total	28,968	30,518
US Treasury & Agency Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements, Remaining contractual maturity of the agreements	30,567	31,633
US Treasury & Agency Securities [Member] | Overnight & Continuous [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements, Remaining contractual maturity of the agreements	1,599	1,115
US Treasury & Agency Securities [Member] | Greater Than 90 Days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Repurchase agreements, Remaining contractual maturity of the agreements	$ 28,968	$ 30,518