Securities, AFS Securities in Continuous Unrealized Loss Position (Details) $ in Thousands	Dec. 31, 2021 USD ($) Position	Dec. 31, 2020 USD ($) Position
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 811,115	$ 213,643
12 months or longer	253,578	800
Total	1,064,693	214,443
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(13,238)	(2,170)
12 months or longer	(8,704)	(9)
Total	$ (21,942)	$ (2,179)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	127	19
12 months or longer | Position	22	4
Total | Position	149	23
AIR on AFS debt securities	$ 3,900	$ 3,300
U.S. Treasury [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	49,105
12 months or longer	0
Total	49,105
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(6)
12 months or longer	0
Total	$ (6)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	2
12 months or longer | Position	0
Total | Position	2
Federal Agency [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 41,618	148,537
12 months or longer	198,313	0
Total	239,931	148,537
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(1,846)	(2,052)
12 months or longer	(6,677)	0
Total	$ (8,523)	$ (2,052)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	4	10
12 months or longer | Position	12	0
Total | Position	16	10
State & Municipal [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 87,515
12 months or longer	0
Total	87,515
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(1,559)
12 months or longer	0
Total	$ (1,559)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	61
12 months or longer | Position	0
Total | Position	61
Mortgage-Backed [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 281,217	$ 47,269
12 months or longer	39,491	800
Total	320,708	48,069
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(4,319)	(60)
12 months or longer	(1,525)	(9)
Total	$ (5,844)	$ (69)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	24	3
12 months or longer | Position	6	4
Total | Position	30	7
Collateralized Mortgage Obligations [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 341,673	$ 17,837
12 months or longer	15,774	0
Total	357,447	17,837
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(5,495)	(58)
12 months or longer	(502)	0
Total	$ (5,997)	$ (58)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	34	6
12 months or longer | Position	4	0
Total | Position	38	6
Corporate [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 9,987
12 months or longer	0
Total	9,987
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(13)
12 months or longer	0
Total	$ (13)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	2
12 months or longer | Position	0
Total | Position	2