Loans Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Receivables [Abstract]
Recorded Investment, loans modified in troubled debt restructuring	$ 4,739	$ 3,958
Restructured Loans Subsequently Accruing	1,000
Ytd Restructured Loans Still On Nonaccrual	4,000
Net unaccreted purchase discount	18,000
Unaccreted purchase discount, performing loans	16,000
Unaccreted purchase discount, nonperforming loans	2,000
Bank Mutual
Financing Receivable, Allowance for Credit Losses [Line Items]
Purchased credit-impaired loans	$ 5,000		$ 5,000