Derivative Financial Instruments - Additional Information (Details) (Interest Rate Swap [Member], Not Designated as Hedging Instrument [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Customer
Customer interest rate swaps (commerical customer counterparty):
Notional amount of assets, Assets	$ 24,485	$ 28,190
Notional amount of assets, Liabilities		1,955
Notional amount of assets, Net total		30,145
Customer interest rate swaps (commerical customer counterparty):
Fair Value of assets, Assets	274	437
Fair Value of assets, Liabilities		(4)
Fair Value of assets, Net total		433
Correspondent
Correspondent interest rate swaps (financial institution counterparty):
Notional amount of liabilities, Assets	24,485	1,955
Notional amount of liabilities, Liabilities		28,190
Notional amount of liabilities, Net total		30,145
Correspondent interest rate swaps (financial institution counterparty):
Fair Value of liabilities, Assets	(287)	4
Fair Value of liabilities, Liabilities		(460)
Fair Value of liabilities, Net total		$ (456)

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