Mortgage Servicing Rights (Narrative) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Mortgage Servicing Rights [Abstract]
Residential Mortgage Loans Serviced	$ 3,400,000,000		$ 3,400,000,000		$ 3,400,000,000
Contractually Specified Servicing Fee, Late Fee, and Ancillary Fee Earned in Exchange for Servicing Financial Asset	2,100,000	$ 2,100,000	4,200,000	$ 4,300,000
Valuation allowance increase	$ 1,784,000	$ 1,069,000	$ (1,339,000)	$ 4,036,000