Securities - Securities in Continuous Unrealized Loss Position (Details) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2016 USD ($) security	Dec. 31, 2015 USD ($) security
Available-for-sale, Continuous Unrealized Loss Position [Abstract]
Amortized Cost, Less than 12 Months	$ 30,789	$ 169,166
Gross Unrealized Losses, Less than 12 Months	(145)	(584)
Fair Value, Less than 12 Months	30,644	168,582
Held-to-maturity, Continuous Unrealized Loss Position [Abstract]
Amortized Cost, Less than 12 Months	1,442	13,165
Gross Unrealized Losses, Less than 12 Months	(1)	(121)
Fair Value, Less than 12 Months	1,441	13,044
Amortized Cost, More than 12 Months	8,893	15,442
Gross Unrealized Losses, More than 12 Months	(139)	(387)
Fair Value, More than 12 Months	$ 8,754	$ 15,055
Investment Securities Continuous Unrealized Loss Position Qualitative Disclosure Abstract
AFS and HTM, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | security	4	6
Securities in Unrealized Loss Position, Continuous Unrealized Loss as percent of Amortized Cost	0.69	0.55
US Treasury and Government [Member]
Available-for-sale, Continuous Unrealized Loss Position [Abstract]
Amortized Cost, Less than 12 Months		$ 85,028
Gross Unrealized Losses, Less than 12 Months		(85)
Fair Value, Less than 12 Months		84,943
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Available-for-sale, Continuous Unrealized Loss Position [Abstract]
Amortized Cost, Less than 12 Months	$ 18,914	48,830
Gross Unrealized Losses, Less than 12 Months	(102)	(184)
Fair Value, Less than 12 Months	18,812	48,646
Held-to-maturity, Continuous Unrealized Loss Position [Abstract]
Amortized Cost, Less than 12 Months		3,220
Gross Unrealized Losses, Less than 12 Months		(48)
Fair Value, Less than 12 Months		3,172
Amortized Cost, More than 12 Months	866	2,571
Gross Unrealized Losses, More than 12 Months	(8)	(95)
Fair Value, More than 12 Months	858	2,476
Collateralized Mortgage Backed Securities [Member]
Available-for-sale, Continuous Unrealized Loss Position [Abstract]
Amortized Cost, Less than 12 Months	10,090	33,299
Gross Unrealized Losses, Less than 12 Months	(28)	(314)
Fair Value, Less than 12 Months	10,062	32,985
Held-to-maturity, Continuous Unrealized Loss Position [Abstract]
Amortized Cost, Less than 12 Months	1,442	9,945
Gross Unrealized Losses, Less than 12 Months	(1)	(73)
Fair Value, Less than 12 Months	1,441	9,872
Amortized Cost, More than 12 Months	8,027	12,871
Gross Unrealized Losses, More than 12 Months	(131)	(292)
Fair Value, More than 12 Months	7,896	12,579
Corporate debt securities
Available-for-sale, Continuous Unrealized Loss Position [Abstract]
Amortized Cost, Less than 12 Months	1,785	2,009
Gross Unrealized Losses, Less than 12 Months	(15)	(1)
Fair Value, Less than 12 Months	$ 1,770	$ 2,008