Fair Value Disclosures, Reconciliation for all Assets Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3) (Details) - Capitalized Mortgage Loan Servicing Rights [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Reconciliation for all assets and (liabilities) measured at fair value on a recurring basis using significant unobservable inputs (Level 3) [Roll Forward]
Beginning balance	$ 16,904	$ 19,171
Total gains (losses) realized and unrealized [Abstract]
Included in results of operations	3,257	(6,974)
Included in other comprehensive income (loss)	0	0
Purchases, issuances, settlements, maturities and calls	3,369	2,632
Transfers in and/or out of Level 3	0	0
Ending balance	23,530	14,829
Amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets and liabilities still held at March 31	$ 3,257	$ (6,974)