Short-Term Borrowings - Components of short-term borrowings (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Short-term Debt [Line Items]
Total short-term borrowings	$ 2,674	$ 4,576
Average balance during the year	3,831	1,803
Weighted-average annual interest rate during the year	3.61%	0.10%
Maximum month-end balance	3,353	4,576
Securities Sold under Agreements to Repurchase
Short-term Debt [Line Items]
Total short-term borrowings	674	1,576
Line of Credit
Short-term Debt [Line Items]
Total short-term borrowings	$ 2,000	$ 3,000