Interest Rate Swap Derivatives - Interest rate swaps designated as cash flow hedges (Details) - Interest Rate Swap Derivatives - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Derivative [Line Items]
Notional Amounts	$ 10,000	$ 10,000
Weighted average pay rates	5.35%	5.35%
Weighted average receive rates	2.05%	1.91%
Weighted average maturity	12 years 6 months 29 days	13 years 29 days
Unrealized losses	$ 2,973	$ 2,013