Accumulated Other Comprehensive Income (Loss) (Schedule of Components of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive income (loss)	$ (4,185)	$ 14,350
Unrealized Gain (Loss) on Securities Available for Sale
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive income (loss)	(3,787)	20,448
Deferred tax asset (liability)	870	(4,699)
Total accumulated other comprehensive income (loss)	(2,917)	15,749
Postretirement Plans Asset (Liability)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive income (loss)	(1,646)	(1,817)
Deferred tax asset (liability)	378	418
Total accumulated other comprehensive income (loss)	(1,268)	(1,399)
Total
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive income (loss)	$ (4,185)	$ 14,350