Fair Value Disclosures, Reconciliation for all Assets and Liabilities 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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Reconciliation for all assets and (liabilities) measured at fair value on a recurring basis using significant unobservable inputs (Level 3) [Roll Forward]
Beginning balance	$ 19,909	$ 17,783	$ 21,400	$ 15,699
Total gains (losses) realized and unrealized [Abstract]
Included in results of operations	(3,422)	(137)	(6,113)	892
Included in other comprehensive income (loss)	0	0	0	0
Purchases, issuances, settlements, maturities and calls	1,407	4,202	2,607	5,257
Transfers in and/or out of Level 3	0	0	0	0
Ending balance	17,894	21,848	17,894	21,848
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 June 30	$ (3,422)	$ (137)	$ (6,113)	$ 892