Loans and Leases (Carrying amount loans not covered by loss share agreements (in text)) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Jul. 02, 2009	Jan. 16, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan and lease losses	$ 41,854,000	$ 41,449,000
Elizabeth State Bank
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contractually required payments of loans acquired			42,700,000
Estimated fair value of loans acquired			37,800,000
Community Banc-Corp of Sheboygan, Inc.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contractually required payments of loans acquired				12,900,000
Estimated fair value of loans acquired				8,200,000
Allowance for loan and lease losses	0
Contractually required payments receivable of nonimpaired loans				400,000,000
Estimated fair value of nonimpaired loans acquired				$ 386,800,000