Securities - Additional Information (Details 4) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Securities Pledged
Securities pledged to various federal reserve districts, amortized cost	$ 100,000	$ 55,000
Securities pledged to various federal reserve districts, fair value	100,000	54,800
Repurchase Agreements [Member]
Securities Pledged
Amortized cost of securities pledged	16,300	17,700
Securities pledged and available to be sold under repurchase agreements, fair value	16,400	17,900
Derivative [Member]
Securities Pledged
Amortized cost of securities pledged	566	669
Securities pledged and available to be sold under repurchase agreements, fair value	$ 592	$ 701