Securities, HTM Securities in Continuous Unrealized Loss Position (Details) $ in Thousands	Dec. 31, 2018 USD ($) Position	Dec. 31, 2017 USD ($) Position
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 23,293	$ 156,340
12 months or longer	286,233	87,037
Total	309,526	243,377
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(91)	(1,336)
12 months or longer	(8,195)	(2,671)
Total	$ (8,286)	$ (4,007)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	32	59
12 months or longer | Position	118	32
Total | Position	150	91
Mortgage-Backed [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 0	$ 15,477
12 months or longer	82,579	33,703
Total	82,579	49,180
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	0	(140)
12 months or longer	(2,773)	(670)
Total	$ (2,773)	$ (810)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	0	2
12 months or longer | Position	6	2
Total | Position	6	4
Collateralized Mortgage Obligations [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 4,386	$ 118,476
12 months or longer	145,396	37,614
Total	149,782	156,090
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(7)	(1,064)
12 months or longer	(3,890)	(1,513)
Total	$ (3,897)	$ (2,577)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	2	17
12 months or longer | Position	26	6
Total | Position	28	23
State & Municipal [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 18,907	$ 22,387
12 months or longer	58,258	15,720
Total	77,165	38,107
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(84)	(132)
12 months or longer	(1,532)	(488)
Total	$ (1,616)	$ (620)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	30	40
12 months or longer | Position	86	24
Total | Position	116	64