v3.26.1
Federal Funds Purchased and Securities Sold Under Agreements to Repurchase - Schedule of Remaining Contractual Maturity in Repurchase Agreements (Detail) - USD ($)
Jun. 30, 2026
Dec. 31, 2025
Assets Sold under Agreements to Repurchase [Line Items]    
Federal funds purchased $ 0 $ 15,000,000
Repurchase agreements, US Treasury & agency securities 14,771,000 37,718,000
Total 14,771,000 37,718,000
US Treasury & Agency Securities [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Repurchase agreements, US Treasury & agency securities 14,771,000 22,718,000
Overnight & Continuous [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Federal funds purchased 0 15,000,000
Repurchase agreements, US Treasury & agency securities 9,000 0
Total 9,000 15,000,000
Up to 30 Days [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Federal funds purchased 0 0
Repurchase agreements, US Treasury & agency securities 0 0
Total 0 0
30-90 Days [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Federal funds purchased 0 0
Repurchase agreements, US Treasury & agency securities 0 0
Total 0 0
Greater Than 90 Days [Member]    
Assets Sold under Agreements to Repurchase [Line Items]    
Federal funds purchased 0 0
Repurchase agreements, US Treasury & agency securities 14,762,000 22,718,000
Total $ 14,762,000 $ 22,718,000