Loans and Leases (Carrying amount loans not covered by loss share agreements (in text)) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Jan. 16, 2015	Dec. 31, 2014	Jul. 02, 2009
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan and lease losses	$ 47,105		$ 41,449
Elizabeth State Bank
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contractually required payments of loans acquired				$ 42,700
Estimated fair value of loans acquired				$ 37,800
Community Banc-Corp of Sheboygan, Inc.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contractually required payments of loans acquired		$ 14,700
Estimated fair value of loans acquired		9,300
Allowance for loan and lease losses	$ 116
Contractually required payments receivable of nonimpaired loans		558,400
Estimated fair value of nonimpaired loans acquired		$ 539,900