Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

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

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Amount of obligation to return cash collateral under master netting arrangements that have not been offset against derivative assets.

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Derivatives - Narrative (Details)	3 Months Ended			6 Months Ended
Derivatives - Narrative (Details)	Jun. 30, 2018 USD ($) derivative_swap	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) derivative_swap	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Derivatives, Fair Value [Line Items]
Collateral requirement threshold				$ 250,000
Collateral posted	$ 300,000			300,000		$ 300,000
Derivative notional amount	$ 11,500,000			$ 11,500,000		12,500,000
Number of derivatives \| derivative_swap	2			2
Derivative fee income	$ 0		$ 16,000	$ 0	$ 16,000
Residential Mortgage Holding Company
Derivatives, Fair Value [Line Items]
Commitments to originate mortgage loans held for sale	84,100,000			84,100,000		$ 43,600,000
Variable to Fixed
Derivatives, Fair Value [Line Items]
Derivative notional amount	$ 5,700,000			$ 5,700,000
Number of derivatives \| derivative_swap	1			1
Fixed to Variable
Derivatives, Fair Value [Line Items]
Derivative notional amount	$ 5,700,000			$ 5,700,000
Number of derivatives \| derivative_swap	1			1
Subordinated Debt
Derivatives, Fair Value [Line Items]
Junior subordinated debenture		$ 10,000,000.0
Junior subordinated debenture, effective interest rate		3.72%
Debt instrument, interest rate during period	3.71%
Subordinated Debt \| LIBOR
Derivatives, Fair Value [Line Items]
Debt instrument, basis spread on variable rate		1.37%
Designated as Hedging Instrument \| Interest rate swaps
Derivatives, Fair Value [Line Items]
Cash pledged to collateralize fair value exposure on interest rate swap	$ 400,000			$ 400,000
Unrealized gain on interest rate swap	$ 805,000			$ 805,000