Derivatives - Two-way client interest rate swaps not designated as either fair value or cash flow hedges (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016 USD ($) position	Dec. 31, 2015 USD ($) position
Derivative [Line Items]
Notional amount	$ 10,786	$ 10,932
Asset	242	73
Liability	$ 242	$ 73
Life (Years)
Interest Rate Swap [Member] | Interest Rate Swap One [Member]
Derivative [Line Items]
Positions | position	1	1
Notional amount	$ 3,698	$ 3,760
Asset	0	0
Liability	$ 128	$ 21
Rate	3.90%	3.90%
Rate	2.00%	2.00%
Life (Years)	11 years 7 months 6 days	11 years 10 months 24 days
Interest Rate Swap [Member] | Interest Rate Swap Two [Member]
Derivative [Line Items]
Positions | position	1	1
Notional amount	$ 1,695	$ 1,706
Asset	0	0
Liability	$ 114	$ 52
Rate	4.09%	4.09%
Rate	1.80%	1.80%
Life (Years)	8 years 7 months 6 days	8 years 10 months 24 days
Reverse Interest Rate Swap [Member] | Interest Rate Swap One [Member]
Derivative [Line Items]
Positions | position	1	1
Notional amount	$ 3,698	$ 3,760
Asset	128	21
Liability	$ 0	$ 0
Rate	3.90%	3.90%
Rate	2.00%	2.00%
Life (Years)	11 years 7 months 6 days	11 years 10 months 24 days
Reverse Interest Rate Swap [Member] | Interest Rate Swap Two [Member]
Derivative [Line Items]
Positions | position	1	1
Notional amount	$ 1,695	$ 1,706
Asset	114	52
Liability	$ 0	$ 0
Rate	4.09%	4.09%
Rate	1.80%	1.80%
Life (Years)	8 years 7 months 6 days	8 years 10 months 24 days