Significant Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2019
Accounting Policies [Abstract]
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Adopted Accounting Standards In the six months ended June 30, 2019, the Company adopted the following new accounting guidance: FASB ASU 2016-02, Leases (Topic 842), was issued February 25, 2016. The provisions of the new standard require lessees to recognize most leases on-balance sheet, increasing reported assets and liabilities. Lessor accounting remains substantially similar to current U.S. GAAP. The Company adopted the ASU provisions effective January 1, 2019, and elected the modified retrospective transition approach. The Company elected the package of practical expedients provided in the ASU, which allowed the Company to rely on lease classification determinations made under prior accounting guidance and forego reevaluation of (i) whether any existing contracts are or contain a lease, (ii) whether existing leases are operating or finance leases, and (iii) the initial direct cost for any existing leases. The Company also elected to combine lease and non-lease components and exempt short-term leases with an original term of one year or less from on-balance sheet recognition. The implementing entry recognized a lease liability of $15.3 million and right-of-use asset of $15.3 million for facilities leases. The change in occupancy and equipment expense was not material. FASB ASU 2017-08, Receivables – Non-Refundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities, was issued March 2017. The ASU shortens the amortization period for certain callable debt securities held at a premium. Specifically, the ASU requires the premium to be amortized to the earliest call date. The ASU does not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. The Company adopted the ASU provisions on January 1, 2019. The implementing entry reduced the carrying value of investment securities, specifically obligations of states and political subdivisions, by $3.1 million and reduced retained earnings by $2.8 million, net of tax. The change in premium amortization method was not material to revenue recognition. FASB ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities, was issued August 2017. The ASU expands and refines hedge accounting for both nonfinancial and financial risk components and aligns the recognition and presentation of the effects of the hedging instrument and the hedged item in the financial statements. The ASU also provides for a one-time reclassification of prepayable assets from held-to-maturity (HTM) to available for sale (AFS) regardless of derivative use. The Company adopted the ASU provisions on January 1, 2019. The Company does not currently engage in trading activities or use derivative instruments to control interest rate risk, even though such activities may be permitted with the approval of the Company’s Board of Directors. The Company evaluated the prepayable assets in the HTM portfolio and did not effect a one-time reclassification of prepayable assets from HTM to the AFS upon implementation. Recently Issued Accounting Standards FASB ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, was issued on June 16, 2016. The ASU significantly changes estimates for credit losses related to financial assets measured at amortized cost and certain other contracts. For estimating credit losses, the FASB is replacing the incurred loss model with the current expected credit loss (CECL) model, which will accelerate recognition of credit losses. Additionally, credit losses relating to debt securities available-for-sale will be recorded through an allowance for credit losses under the new standard. The Company will also be required to provide additional disclosures related to the financial assets within the scope of the new standard. The Company will be required to adopt the ASU provisions on January 1, 2020. Management has evaluated available data, defined portfolio segments of loans with similar attributes, and selected loss estimate models for each identified loan portfolio segment. Management has preliminarily measured historical loss rates for each portfolio segment. Management has also segmented debt securities held to maturity, selected methods to estimate losses for each segment, and preliminarily measured a loss estimate. The ultimate adjustment to the allowance for loan losses will be accomplished through an offsetting after-tax adjustment to shareholders’ equity. Economic conditions and the composition of the Company’s loan portfolio and debt securities held to maturity at the time of adoption will influence the extent of the adopting accounting adjustment. Management expects to develop an aggregate loss estimate by December 31, 2019. FASB ASU 2018-13, Fair Value Measurements (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement, was issued August 2018. The ASU is part of the disclosure framework project, where the primary focus is to improve the effectiveness of disclosures in the financial statements. The ASU removes, modifies and adds disclosure requirements related to Fair Value Measurements. The provisions of the ASU are effective January 1, 2020 with the option to early adopt any removed or modified disclosures upon issuance of the ASU. The Company early adopted the provisions to remove and/or modify relevant disclosures in the “Fair Value Measurements” note to the unaudited consolidated financial statements. The requirement to include additional disclosures will be adopted by the Company January 1, 2020. The additional disclosures will not affect the financial results upon adoption.

Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2019

New Accounting Pronouncements, Policy [Policy Text Block]

Recently Adopted Accounting Standards

In the six months ended June 30, 2019, the Company adopted the following new accounting guidance:

FASB ASU 2016-02, Leases (Topic 842), was issued February 25, 2016. The provisions of the new standard require lessees to recognize most leases on-balance sheet, increasing reported assets and liabilities. Lessor accounting remains substantially similar to current U.S. GAAP.

The Company adopted the ASU provisions effective January 1, 2019, and elected the modified retrospective transition approach. The Company elected the package of practical expedients provided in the ASU, which allowed the Company to rely on lease classification determinations made under prior accounting guidance and forego reevaluation of (i) whether any existing contracts are or contain a lease, (ii) whether existing leases are operating or finance leases, and (iii) the initial direct cost for any existing leases. The Company also elected to combine lease and non-lease components and exempt short-term leases with an original term of one year or less from on-balance sheet recognition. The implementing entry recognized a lease liability of $15.3 million and right-of-use asset of $15.3 million for facilities leases. The change in occupancy and equipment expense was not material.

FASB ASU 2017-08, Receivables – Non-Refundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities, was issued March 2017. The ASU shortens the amortization period for certain callable debt securities held at a premium. Specifically, the ASU requires the premium to be amortized to the earliest call date. The ASU does not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity.

The Company adopted the ASU provisions on January 1, 2019. The implementing entry reduced the carrying value of investment securities, specifically obligations of states and political subdivisions, by $3.1 million and reduced retained earnings by $2.8 million, net of tax. The change in premium amortization method was not material to revenue recognition.

FASB ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities, was issued August 2017. The ASU expands and refines hedge accounting for both nonfinancial and financial risk components and aligns the recognition and presentation of the effects of the hedging instrument and the hedged item in the financial statements. The ASU also provides for a one-time reclassification of prepayable assets from held-to-maturity (HTM) to available for sale (AFS) regardless of derivative use.

The Company adopted the ASU provisions on January 1, 2019. The Company does not currently engage in trading activities or use derivative instruments to control interest rate risk, even though such activities may be permitted with the approval of the Company’s Board of Directors. The Company evaluated the prepayable assets in the HTM portfolio and did not effect a one-time reclassification of prepayable assets from HTM to the AFS upon implementation.

Recently Issued Accounting Standards

FASB ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, was issued on June 16, 2016. The ASU significantly changes estimates for credit losses related to financial assets measured at amortized cost and certain other contracts. For estimating credit losses, the FASB is replacing the incurred loss model with the current expected credit loss (CECL) model, which will accelerate recognition of credit losses. Additionally, credit losses relating to debt securities available-for-sale will be recorded through an allowance for credit losses under the new standard. The Company will also be required to provide additional disclosures related to the financial assets within the scope of the new standard.

The Company will be required to adopt the ASU provisions on January 1, 2020. Management has evaluated available data, defined portfolio segments of loans with similar attributes, and selected loss estimate models for each identified loan portfolio segment. Management has preliminarily measured historical loss rates for each portfolio segment. Management has also segmented debt securities held to maturity, selected methods to estimate losses for each segment, and preliminarily measured a loss estimate. The ultimate adjustment to the allowance for loan losses will be accomplished through an offsetting after-tax adjustment to shareholders’ equity. Economic conditions and the composition of the Company’s loan portfolio and debt securities held to maturity at the time of adoption will influence the extent of the adopting accounting adjustment. Management expects to develop an aggregate loss estimate by December 31, 2019.

FASB ASU 2018-13, Fair Value Measurements (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement, was issued August 2018. The ASU is part of the disclosure framework project, where the primary focus is to improve the effectiveness of disclosures in the financial statements. The ASU removes, modifies and adds disclosure requirements related to Fair Value Measurements.

The provisions of the ASU are effective January 1, 2020 with the option to early adopt any removed or modified disclosures upon issuance of the ASU. The Company early adopted the provisions to remove and/or modify relevant disclosures in the “Fair Value Measurements” note to the unaudited consolidated financial statements. The requirement to include additional disclosures will be adopted by the Company January 1, 2020. The additional disclosures will not affect the financial results upon adoption.