Securities - Additional Information (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Securities Pledged
Securities pledged to various federal reserve districts, amortized cost	$ 55,000,000	$ 38,200,000
Securities pledged to various federal reserve districts, fair value	54,800,000	37,500,000
Repurchase Agreements [Member]
Securities Pledged
Amortized cost of securities pledged	17,700,000	10,300,000
Securities pledged and available to be sold under repurchase agreements, fair value	17,900,000	10,500,000
Derivative [Member]
Securities Pledged
Amortized cost of securities pledged	669,000	895,000
Securities pledged and available to be sold under repurchase agreements, fair value	$ 701,000	$ 929,000