FHLB Advances (Details Textual) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
FHLB Advances	$ 525,153,000	$ 410,200,000
Investment securities pledged	339,100,000	362,800,000
Maximum borrowing capacity	$ 494,300,000
Minimum
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Interest rate (as a percent)	1.06%
Maximum
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Interest rate (as a percent)	3.26%
Weighted Average
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Interest rate (as a percent)	2.15%
Federal Home Loan Bank, Advances, Putable Option
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Variable rate advances	$ 230,000,000.0
Residential mortgage
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Loans pledged	238,600,000	226,300,000
Commercial and industrial
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Loans pledged	$ 881,700,000	$ 808,900,000

Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

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Discloses the single interest rate [if] applicable to the advances from the Federal Home Loan Bank, by branch, as of the Balance Sheet date.

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-Publisher FASB
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Amount of Federal Home Loan Bank (FHLB) advances which have floating interest rates.

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-SubTopic 210
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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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The fair value, as of the date of each statement of financial position presented, of loans that are restricted as collateral for the payment of the FHLB debt obligations, and that are reclassified and separately reported in the statement of financial position because the transferee has the right by contract or custom to sell or re-pledge them.

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The fair value, as of the date of each statement of financial position presented, of securities which are owned but transferred to serve as collateral for the payment of the FHLB debt obligations, and that are reclassified and separately reported in the statement of financial position because the transferee has the right by contract or custom to sell or re-pledge them.

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