Loans - Accretable yield on the purchased credit impaired (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accretable yield on purchased credit impaired
Balance at the beginning of period	$ 2,726	$ 1,403	$ 1,676
Accretable yield at acquisition	788	602	0
Accretion	(1,354)	(385)	(255)
Disposals and other	165	(249)	(18)
Change in accretable yield	1,422	1,355	0
Balance at the end of period	$ 3,747	$ 2,726	$ 1,403