Residential Mortgage Servicing Rights (Sensitivity Analysis of Current Fair Value to Changes in Discount and Prepayment Speed Assumptions) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Transfers and Servicing [Abstract]
Effect on fair value of a 10% adverse change	$ (5,611)	$ (5,410)
Effect on fair value of a 20% adverse change	(10,833)	(10,403)
Effect on fair value of a 100 basis point adverse change	(3,339)	(4,366)
Effect on fair value of a 200 basis point adverse change	$ (6,448)	$ (8,418)