Short and Long-Term Borrowings Junior Subordinated Debentures (Details) - USD ($)	9 Months Ended
Sep. 30, 2019	Dec. 31, 2018
Junior Subordinated Debentures
Par	$ 38,249,000
Unamortized Discount	(7,794,000)
Carrying value	30,455,000	$ 30,096,000
2005 Mid-Wisconsin Financial Services, Inc.
Junior Subordinated Debentures
Par	10,310,000
Unamortized Discount	(3,222,000)
Carrying value	$ 7,088,000	$ 6,939,000
Stated interest rate	3.55%	4.22%
2006 Baylake Corp.
Junior Subordinated Debentures
Par	$ 16,598,000
Unamortized Discount	(3,942,000)
Carrying value	$ 12,656,000	$ 12,478,000
Stated interest rate	3.45%	4.15%
2004 First Menasha Bancshares, Inc.
Junior Subordinated Debentures
Par	$ 5,155,000
Unamortized Discount	(630,000)
Carrying value	$ 4,525,000	$ 4,493,000
Stated interest rate	4.93%	5.58%
2004 Nicolet Bankshares Statutory Trust
Junior Subordinated Debentures
Par	$ 6,186,000
Unamortized Discount	0
Carrying value	$ 6,186,000	$ 6,186,000
Stated interest rate	8.00%
London Interbank Offered Rate (LIBOR) \| 2005 Mid-Wisconsin Financial Services, Inc.
Junior Subordinated Debentures
Floating interest rate	1.43%
London Interbank Offered Rate (LIBOR) \| 2006 Baylake Corp.
Junior Subordinated Debentures
Floating interest rate	1.35%
London Interbank Offered Rate (LIBOR) \| 2004 First Menasha Bancshares, Inc.
Junior Subordinated Debentures
Floating interest rate	2.79%

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

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- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Amount, after accumulated amortization, of debt discount.

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- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of long-term debt (with maturities initially due after one year or beyond the operating cycle if longer) identified as Junior Subordinated Notes, which have a lower priority than senior instruments.

+ References

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