Investment Securities - Unrealized Losses (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) security	Dec. 31, 2015 USD ($) security
Investment securities
Less Than Twelve Months, Fair Value	$ 228,559	$ 213,195
Less Than Twelve Months, Unrealized Loss	(5,439)	(2,542)
Twelve Months or More, Fair Value	60,017	50,336
Twelve Months or More, Unrealized Loss	(1,319)	(1,395)
Total, Fair Value	288,576	263,531
Total, Unrealized Loss	$ (6,758)	$ (3,937)
Securities in an unrealized loss position
Securities in an unrealized loss position | security	138	104
Investment security holdings | Minimum
Securities in an unrealized loss position
Maturity period of available-for-sale securities	1 year
Investment security holdings | Maximum
Securities in an unrealized loss position
Maturity period of available-for-sale securities	40 years
Obligations of U.S. government agencies
Investment securities
Less Than Twelve Months, Fair Value	$ 21,704	$ 34,533
Less Than Twelve Months, Unrealized Loss	(78)	(429)
Twelve Months or More, Fair Value	29,879
Twelve Months or More, Unrealized Loss	(503)
Total, Fair Value	51,583	34,533
Total, Unrealized Loss	(581)	(429)
Mortgage-backed securities - U.S. government sponsored entities and agencies
Investment securities
Less Than Twelve Months, Fair Value	142,895	131,570
Less Than Twelve Months, Unrealized Loss	(3,098)	(1,485)
Twelve Months or More, Fair Value	20,733	31,558
Twelve Months or More, Unrealized Loss	(627)	(827)
Total, Fair Value	163,628	163,128
Total, Unrealized Loss	(3,725)	(2,312)
Mortgage-backed securities - Non-agency
Investment securities
Less Than Twelve Months, Fair Value	9,433	31,400
Less Than Twelve Months, Unrealized Loss	(29)	(317)
Twelve Months or More, Fair Value	634	2,917
Twelve Months or More, Unrealized Loss	(4)	(11)
Total, Fair Value	10,067	34,317
Total, Unrealized Loss	(33)	(328)
State and municipal securities
Investment securities
Less Than Twelve Months, Fair Value	54,527	15,660
Less Than Twelve Months, Unrealized Loss	(2,234)	(243)
Twelve Months or More, Fair Value		235
Twelve Months or More, Unrealized Loss		(1)
Total, Fair Value	54,527	15,895
Total, Unrealized Loss	(2,234)	(244)
Asset backed securities
Investment securities
Twelve Months or More, Fair Value	8,771	15,626
Twelve Months or More, Unrealized Loss	(185)	(556)
Total, Fair Value	8,771	15,626
Total, Unrealized Loss	$ (185)	(556)
Other investments
Investment securities
Less Than Twelve Months, Fair Value		32
Less Than Twelve Months, Unrealized Loss		(68)
Total, Fair Value		32
Total, Unrealized Loss		$ (68)