XML 50 R39.htm IDEA: XBRL DOCUMENT v3.21.2
Securities - Gross Unrealized Losses, Aggregated by Investment Category and Length of Time (Detail) - USD ($)
$ in Thousands
Sep. 30, 2021
Dec. 31, 2020
Schedule of Available-for-sale Securities [Line Items]    
Gross Unrealized Losses, Less Than Twelve Months $ (3,281) $ (140)
Fair Value, Less Than Twelve Months 234,792 51,893
Gross Unrealized Losses, Twelve Months and Over (126)  
Fair Value, Twelve Months and Over 4,946  
Gross Unrealized Losses, Total (3,407) (140)
Fair Value, Total 239,738 51,893
U.S. Treasury [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Gross Unrealized Losses, Less Than Twelve Months (572)  
Fair Value, Less Than Twelve Months 58,913  
Gross Unrealized Losses, Total (572)  
Fair Value, Total 58,913  
U.S. Government Agencies [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Gross Unrealized Losses, Less Than Twelve Months (1,636) (130)
Fair Value, Less Than Twelve Months 107,353 48,331
Gross Unrealized Losses, Twelve Months and Over (62)  
Fair Value, Twelve Months and Over 2,443  
Gross Unrealized Losses, Total (1,698) (130)
Fair Value, Total 109,796 48,331
Mortgage-backed Securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Gross Unrealized Losses, Less Than Twelve Months (907)  
Fair Value, Less Than Twelve Months 57,266  
Gross Unrealized Losses, Total (907)  
Fair Value, Total 57,266  
State and Local Governments [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Gross Unrealized Losses, Less Than Twelve Months (166) (10)
Fair Value, Less Than Twelve Months 11,260 3,562
Gross Unrealized Losses, Twelve Months and Over (64)  
Fair Value, Twelve Months and Over 2,503  
Gross Unrealized Losses, Total (230) (10)
Fair Value, Total $ 13,763 $ 3,562