Accumulated Other Comprehensive Loss (Reclassification out of Accumulated Other Comprehensive Income) (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2020
Jun. 30, 2020
Mar. 31, 2020
Sep. 30, 2019
Jun. 30, 2019
Mar. 31, 2019
Sep. 30, 2020
Sep. 30, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                
Net gains $ 1,176     $ 40     $ 2,011 $ 84
Tax (expense) benefit (1,396)     (938)     (2,629) (2,605)
Net income 4,960 $ 2,570 $ 1,755 4,493 $ 2,602 $ 3,151 9,285 10,247
Reclassification out of Accumulated Other Comprehensive Income [Member]                
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                
Net income 108     (238)     (870) (717)
Investment securities- with OTTI [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]                
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                
Interest income expense securities taxable 50     50     151 149
Tax (expense) benefit (13)     (13)     (40) (39)
Net income 37     37     111 110
Investment Securities -All Other AFS [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]                
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                
Net gains 575     1     622 1
Tax (expense) benefit (154)           (167)  
Net income 421     1     455 1
Investment Securities HTM [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]                
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                
Net gains             60  
Interest income expense securities taxable (74)     (82)     (809) (243)
Tax (expense) benefit 20     22     201 65
Net income (54)     (60)     (548) (178)
Pension Plan [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]                
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                
Salaries and employee benefits (358)     (269)        
Tax (expense) benefit 96     73     288 219
Net income (262)     (196)     (786) (588)
Pension Plan [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Amortization of Unrecognized Loss [Member]                
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                
Other expense             (1,074) (807)
SERP [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]                
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                
Tax (expense) benefit 12     8     37 23
Net income (34)     (20)     (102) (62)
SERP [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Amortization of Unrecognized Loss [Member]                
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                
Other expense             (141) (87)
Salaries and employee benefits (47)     (29)        
SERP [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Amortization of Prior Service Costs [Member]                
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                
Salaries and employee benefits $ 1     $ 1     $ 2 $ 2