Derivatives - Designated as a cash flow hedge (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016 USD ($) position	Dec. 31, 2015 USD ($) position	Nov. 25, 2013 USD ($)	Oct. 23, 2010 USD ($)
Derivative [Line Items]
Notional amount	$ 10,786	$ 10,932
Life (Years)
Hedging Instrument [Member]
Derivative [Line Items]
Notional amount				$ 5,200
Pay rate (as a percent)				2.59%
Hedging Instrument [Member] | Interest Rate Swap 2 [Member]
Derivative [Line Items]
Notional amount			$ 10,000
Pay rate (as a percent)			1.43%
Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Positions | position	1	1
Notional amount	$ 5,155	$ 5,155
Asset	0	0
Liability	$ 346	$ 226
Receive rate (as a percent)	0.62%	0.32%
Pay rate (as a percent)	2.59%	2.59%
Life (Years)	4 years 6 months	4 years 9 months 18 days
Hedging Instrument [Member] | Pay fixed receive floating rate interest rate swap [Member]
Derivative [Line Items]
Positions | position	1	1
Notional amount	$ 10,000	$ 10,000
Asset	0	0
Liability	$ 178	$ 71
Receive rate (as a percent)	0.434%	0.23%
Pay rate (as a percent)	1.43%	1.43%
Life (Years)	2 years 8 months 12 days	3 years