Securities (Held to maturity securities losses) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair Value
Less than 12 months	$ 6,278	$ 31,479
12 months or longer	8,894	2,017
Total	15,172	33,496
Unrealized Losses
Less than 12 months	(43)	(884)
12 months or longer	(648)	(261)
Total	(691)	(1,145)
Obligations of states and political subdivisions
Fair Value
Less than 12 months	6,278	31,479
12 months or longer	8,894	2,017
Total	15,172	33,496
Unrealized Losses
Less than 12 months	(43)	(884)
12 months or longer	(648)	(261)
Total	$ (691)	$ (1,145)