Investment securities Investment Securities Held-to-Maturity by Security Type (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity securities	$ 51,259	$ 51,343
Held-to-maturity securities, fair value	51,918	51,501
State and political subdivisions [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity securities	51,259	51,343
Gross unrealized gains	883	344
Gross unrealized losses	(224)	(186)
Held-to-maturity securities, fair value	$ 51,918	$ 51,501