Long-Term Debt (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2019	Dec. 31, 2018
Long-Term Debt
Face Value	$ 62,700	$ 62,700
Carrying Amount	58,775	58,824
Letter of credit with FHLB
Long-Term Debt
Outstanding letters of credit	150	150
Letter of credit with Bank of North Dakota
Long-Term Debt
Collateralized loans	244,800	260,600
Outstanding letters of credit	0	0
Subordinated notes payable
Long-Term Debt
Face Value	50,000	50,000
Carrying Amount	$ 49,609	$ 49,562
Fixed interest rate	5.75%	5.75%
Junior subordinated debenture (Trust I)
Long-Term Debt
Face Value	$ 4,000	$ 4,000
Carrying Amount	$ 3,390	$ 3,357
Period End Interest Rate	5.21%	5.92%
Junior subordinated debenture (Trust I) \| Three - month LIBOR
Long-Term Debt
Interest Rate	3.10%	3.10%
Junior subordinated debenture (Trust II)
Long-Term Debt
Face Value	$ 6,000	$ 6,000
Carrying Amount	$ 5,086	$ 5,035
Period End Interest Rate	3.92%	4.59%
Junior subordinated debenture (Trust II) \| Three - month LIBOR
Long-Term Debt
Interest Rate	1.80%	1.80%
Finance lease liability
Long-Term Debt
Face Value	$ 2,700
Carrying Amount	$ 690
Fixed interest rate	7.81%
Obligations under capital lease
Long-Term Debt
Face Value		$ 2,700
Carrying Amount		$ 870
Fixed interest rate		7.81%

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

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- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

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- Definition

Amount of assets pledged to secure a debt instrument.

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- Definition

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

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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

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

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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.

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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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