Loans, Impaired Loans Recorded Investment, Unpaid Principal Balance, Related Allowance, Average Recorded Investment, and Interest Income Recognized (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	$ 110,043
Impaired Financing Receivable, Unpaid Principal Balance	148,020
Impaired Financing Receivable, Related Allowance	16,165
Impaired Financing Receivable, Average Recorded Investment	113,697
Interest Income Recognized	$ 3,628
Net Recorded Investment of the Impaired Loans	63.00%
Bank Mutual [Member]
Loan and Lease Receivables, Impaired [Abstract]
purchased credit-impaired loans	$ 2,000
Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	76,102
Impaired Financing Receivable, Unpaid Principal Balance	95,033
Impaired Financing Receivable, Related Allowance	16,165
Impaired Financing Receivable, Average Recorded Investment	77,235
Interest Income Recognized	3,012
Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	33,941
Impaired Financing Receivable, Unpaid Principal Balance	52,987
Impaired Financing Receivable, Related Allowance	0
Impaired Financing Receivable, Average Recorded Investment	36,462
Interest Income Recognized	616
Commercial and industrial
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	62,035
Impaired Financing Receivable, Unpaid Principal Balance	96,784
Impaired Financing Receivable, Related Allowance	12,010
Impaired Financing Receivable, Average Recorded Investment	65,792
Interest Income Recognized	1,895
Commercial and industrial | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	47,249
Impaired Financing Receivable, Unpaid Principal Balance	63,346
Impaired Financing Receivable, Related Allowance	12,010
Impaired Financing Receivable, Average Recorded Investment	45,290
Interest Income Recognized	1,832
Commercial and industrial | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	14,787
Impaired Financing Receivable, Unpaid Principal Balance	33,438
Impaired Financing Receivable, Related Allowance	0
Impaired Financing Receivable, Average Recorded Investment	20,502
Interest Income Recognized	63
Commercial real estate - owner occupied
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	1,676
Impaired Financing Receivable, Unpaid Principal Balance	1,682
Impaired Financing Receivable, Related Allowance	19
Impaired Financing Receivable, Average Recorded Investment	1,774
Interest Income Recognized	88
Commercial real estate - owner occupied | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	1,676
Impaired Financing Receivable, Unpaid Principal Balance	1,682
Impaired Financing Receivable, Related Allowance	19
Impaired Financing Receivable, Average Recorded Investment	1,774
Interest Income Recognized	88
Commercial real estate - owner occupied | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	0
Impaired Financing Receivable, Unpaid Principal Balance	0
Impaired Financing Receivable, Related Allowance	0
Impaired Financing Receivable, Average Recorded Investment	0
Interest Income Recognized	0
Commercial and business lending
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	63,711
Impaired Financing Receivable, Unpaid Principal Balance	98,466
Impaired Financing Receivable, Related Allowance	12,029
Impaired Financing Receivable, Average Recorded Investment	67,566
Interest Income Recognized	1,982
Commercial and business lending | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	48,924
Impaired Financing Receivable, Unpaid Principal Balance	65,028
Impaired Financing Receivable, Related Allowance	12,029
Impaired Financing Receivable, Average Recorded Investment	47,064
Interest Income Recognized	1,919
Commercial and business lending | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	14,787
Impaired Financing Receivable, Unpaid Principal Balance	33,438
Impaired Financing Receivable, Related Allowance	0
Impaired Financing Receivable, Average Recorded Investment	20,502
Interest Income Recognized	63
Commercial real estate - investor
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	4,633
Impaired Financing Receivable, Unpaid Principal Balance	5,808
Impaired Financing Receivable, Related Allowance	15
Impaired Financing Receivable, Average Recorded Investment	4,931
Interest Income Recognized	174
Commercial real estate - investor | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	928
Impaired Financing Receivable, Unpaid Principal Balance	2,104
Impaired Financing Receivable, Related Allowance	15
Impaired Financing Receivable, Average Recorded Investment	950
Interest Income Recognized	15
Commercial real estate - investor | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	3,705
Impaired Financing Receivable, Unpaid Principal Balance	3,705
Impaired Financing Receivable, Related Allowance	0
Impaired Financing Receivable, Average Recorded Investment	3,980
Interest Income Recognized	159
Real estate construction
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	477
Impaired Financing Receivable, Unpaid Principal Balance	559
Impaired Financing Receivable, Related Allowance	67
Impaired Financing Receivable, Average Recorded Investment	494
Interest Income Recognized	30
Real estate construction | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	477
Impaired Financing Receivable, Unpaid Principal Balance	559
Impaired Financing Receivable, Related Allowance	67
Impaired Financing Receivable, Average Recorded Investment	494
Interest Income Recognized	30
Real estate construction | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	0
Impaired Financing Receivable, Unpaid Principal Balance	0
Impaired Financing Receivable, Related Allowance	0
Impaired Financing Receivable, Average Recorded Investment	0
Interest Income Recognized	0
Commercial real estate lending
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	5,110
Impaired Financing Receivable, Unpaid Principal Balance	6,367
Impaired Financing Receivable, Related Allowance	82
Impaired Financing Receivable, Average Recorded Investment	5,425
Interest Income Recognized	204
Commercial real estate lending | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	1,405
Impaired Financing Receivable, Unpaid Principal Balance	2,663
Impaired Financing Receivable, Related Allowance	82
Impaired Financing Receivable, Average Recorded Investment	1,445
Interest Income Recognized	45
Commercial real estate lending | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	3,705
Impaired Financing Receivable, Unpaid Principal Balance	3,705
Impaired Financing Receivable, Related Allowance	0
Impaired Financing Receivable, Average Recorded Investment	3,980
Interest Income Recognized	159
Total commercial
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	68,820
Impaired Financing Receivable, Unpaid Principal Balance	104,833
Impaired Financing Receivable, Related Allowance	12,111
Impaired Financing Receivable, Average Recorded Investment	72,991
Interest Income Recognized	2,186
Total commercial | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	50,329
Impaired Financing Receivable, Unpaid Principal Balance	67,691
Impaired Financing Receivable, Related Allowance	12,111
Impaired Financing Receivable, Average Recorded Investment	48,509
Interest Income Recognized	1,965
Total commercial | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	18,491
Impaired Financing Receivable, Unpaid Principal Balance	37,142
Impaired Financing Receivable, Related Allowance	0
Impaired Financing Receivable, Average Recorded Investment	24,482
Interest Income Recognized	222
Residential mortgage
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	35,554
Impaired Financing Receivable, Unpaid Principal Balance	37,087
Impaired Financing Receivable, Related Allowance	2,740
Impaired Financing Receivable, Average Recorded Investment	34,683
Interest Income Recognized	1,229
Residential mortgage | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	21,450
Impaired Financing Receivable, Unpaid Principal Balance	22,625
Impaired Financing Receivable, Related Allowance	2,740
Impaired Financing Receivable, Average Recorded Investment	23,721
Interest Income Recognized	856
Residential mortgage | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	14,104
Impaired Financing Receivable, Unpaid Principal Balance	14,461
Impaired Financing Receivable, Related Allowance	0
Impaired Financing Receivable, Average Recorded Investment	10,962
Interest Income Recognized	373
Home equity
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	4,422
Impaired Financing Receivable, Unpaid Principal Balance	4,851
Impaired Financing Receivable, Related Allowance	1,190
Impaired Financing Receivable, Average Recorded Investment	4,773
Interest Income Recognized	211
Home equity | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	3,076
Impaired Financing Receivable, Unpaid Principal Balance	3,468
Impaired Financing Receivable, Related Allowance	1,190
Impaired Financing Receivable, Average Recorded Investment	3,756
Interest Income Recognized	191
Home equity | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	1,346
Impaired Financing Receivable, Unpaid Principal Balance	1,383
Impaired Financing Receivable, Related Allowance	0
Impaired Financing Receivable, Average Recorded Investment	1,017
Interest Income Recognized	21
Other consumer
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	1,247
Impaired Financing Receivable, Unpaid Principal Balance	1,249
Impaired Financing Receivable, Related Allowance	125
Impaired Financing Receivable, Average Recorded Investment	1,250
Interest Income Recognized	1
Other consumer | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	1,247
Impaired Financing Receivable, Unpaid Principal Balance	1,249
Impaired Financing Receivable, Related Allowance	125
Impaired Financing Receivable, Average Recorded Investment	1,250
Interest Income Recognized	1
Other consumer | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	0
Impaired Financing Receivable, Unpaid Principal Balance	0
Impaired Financing Receivable, Related Allowance	0
Impaired Financing Receivable, Average Recorded Investment	0
Interest Income Recognized	0
Total consumer
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	41,223
Impaired Financing Receivable, Unpaid Principal Balance	43,187
Impaired Financing Receivable, Related Allowance	4,055
Impaired Financing Receivable, Average Recorded Investment	40,706
Interest Income Recognized	1,441
Total consumer | Loans with a related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	25,773
Impaired Financing Receivable, Unpaid Principal Balance	27,342
Impaired Financing Receivable, Related Allowance	4,055
Impaired Financing Receivable, Average Recorded Investment	28,726
Interest Income Recognized	1,047
Total consumer | Loans with no related allowance
Loan and Lease Receivables, Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	15,450
Impaired Financing Receivable, Unpaid Principal Balance	15,845
Impaired Financing Receivable, Related Allowance	0
Impaired Financing Receivable, Average Recorded Investment	11,979
Interest Income Recognized	$ 394