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Derivative Financial Instruments and Hedging Activities - Narrative (Details) - Fair value hedge $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($) derivative	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)
Derivatives, Fair Value [Line Items]
Net hedge ineffectiveness gain (loss), derivatives	$ (6)	$ 162
Interest income
Derivatives, Fair Value [Line Items]
Increase (decrease) in value of designated interest rate swaps due to LIBOR interest rate movements recognized in interest income	111	(876)
Payment on interest rate swaps recorded in interest income	(98)	(174)
(Decrease) increase in value of hedged loans recognized in interest income	(113)	1,050
Decrease in value of yield maintenance agreement recognized against interest income	(4)	(12)
Net loss on derivatives recognized against interest income	(104)	$ (12)
Designated as hedging instrument
Derivatives, Fair Value [Line Items]
Accrued interest on swaps	$ 12		$ 13
Interest rate swap | Designated as hedging instrument
Derivatives, Fair Value [Line Items]
Number of derivative instruments | derivative	5
Interest rate swap | Designated as hedging instrument | Other assets
Derivatives, Fair Value [Line Items]
Interest rate contracts notional amount, Asset derivatives	$ 4,168		4,217
Interest rate swap | Designated as hedging instrument | Other liabilities
Derivatives, Fair Value [Line Items]
Interest rate contracts notional amount, Liability derivatives	15,324		15,495
Interest rate contract | Designated as hedging instrument | Other assets
Derivatives, Fair Value [Line Items]
Interest rate contracts fair value, Asset derivatives	70		55
Interest rate contract | Designated as hedging instrument | Other liabilities
Derivatives, Fair Value [Line Items]
Interest rate contracts fair value, Liability derivatives	$ 837		$ 933

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