Securities, AFS Securities in Continuous Unrealized Loss Position (Details) $ in Thousands	Dec. 31, 2020 USD ($) Position	Dec. 31, 2019 USD ($) Position
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 213,643	$ 198,501
12 months or longer	800	97,243
Total	214,443	295,744
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(2,170)	(718)
12 months or longer	(9)	(815)
Total	$ (2,179)	$ (1,533)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	19	48
12 months or longer | Position	4	34
Total | Position	23	82
AIR on AFS debt securities	$ 3,300
Federal Agency [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	148,537	$ 14,891
12 months or longer	0	9,866
Total	148,537	24,757
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(2,052)	(109)
12 months or longer	0	(134)
Total	$ (2,052)	$ (243)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	10	2
12 months or longer | Position	0	1
Total | Position	10	3
State & Municipal [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months		$ 2,503
12 months or longer		0
Total		2,503
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months		(20)
12 months or longer		0
Total		$ (20)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position		1
12 months or longer | Position		0
Total | Position		1
Mortgage-Backed [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 47,269	$ 67,986
12 months or longer	800	37,745
Total	48,069	105,731
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(60)	(273)
12 months or longer	(9)	(122)
Total	$ (69)	$ (395)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	3	21
12 months or longer | Position	4	16
Total | Position	7	37
Collateralized Mortgage Obligations [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 17,837	$ 113,121
12 months or longer	0	49,632
Total	17,837	162,753
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(58)	(316)
12 months or longer	0	(559)
Total	$ (58)	$ (875)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	6	24
12 months or longer | Position	0	17
Total | Position	6	41