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, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) [Roll Forward]
Beginning balance	$ 17,783	$ 14,727	$ 15,699	$ 0
Change in accounting	0	0	0	14,213
Total gains (losses) realized and unrealized [Abstract]
Included in results of operations	(137)	(1,231)	892	(1,495)
Included in other comprehensive income (loss)	0	0	0	0
Purchases, issuances, settlements, maturities and calls	4,202	1,019	5,257	1,797
Transfers in and/or out of Level 3	0	0	0	0
Ending balance	21,848	14,515	21,848	14,515
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	(137)	(1,231)	892	(1,495)
As Adjusted [Member]
Reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) [Roll Forward]
Beginning balance	$ 17,783	$ 14,727	$ 15,699	$ 14,213