Securities, HTM Securities in Continuous Unrealized Loss Position (Details) $ in Thousands	Sep. 30, 2019 USD ($) Position	Dec. 31, 2018 USD ($) Position
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 24,103	$ 23,293
12 months or longer	50,544	286,233
Total	74,647	309,526
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(143)	(91)
12 months or longer	(427)	(8,195)
Total	$ (570)	$ (8,286)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	11	32
12 months or longer | Position	7	118
Total | Position	18	150
Mortgage-Backed [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 0	$ 0
12 months or longer	26,836	82,579
Total	26,836	82,579
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	0	0
12 months or longer	(127)	(2,773)
Total	$ (127)	$ (2,773)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	0	0
12 months or longer | Position	2	6
Total | Position	2	6
Collateralized Mortgage Obligations [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 18,656	$ 4,386
12 months or longer	23,708	145,396
Total	42,364	149,782
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(129)	(7)
12 months or longer	(300)	(3,890)
Total	$ (429)	$ (3,897)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	3	2
12 months or longer | Position	5	26
Total | Position	8	28
State & Municipal [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 5,447	$ 18,907
12 months or longer	0	58,258
Total	5,447	77,165
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(14)	(84)
12 months or longer	0	(1,532)
Total	$ (14)	$ (1,616)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	8	30
12 months or longer | Position	0	86
Total | Position	8	116