Securities, AFS Securities in Continuous Unrealized Loss Position (Details) $ in Thousands	Sep. 30, 2022 USD ($) Position	Dec. 31, 2021 USD ($) Position
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 821,157	$ 811,115
12 months or longer	728,991	253,578
Total	1,550,148	1,064,693
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(80,464)	(13,238)
12 months or longer	(141,587)	(8,704)
Total	$ (222,051)	$ (21,942)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	297	127
12 months or longer | Position	118	22
Total | Position	415	149
AIR on AFS debt securities	$ 4,300	$ 3,900
U.S. Treasury [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	120,622	49,105
12 months or longer	0	0
Total	120,622	49,105
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(11,978)	(6)
12 months or longer	0	0
Total	$ (11,978)	$ (6)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	8	2
12 months or longer | Position	0	0
Total | Position	8	2
Federal Agency [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 0	$ 41,618
12 months or longer	204,790	198,313
Total	204,790	239,931
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	0	(1,846)
12 months or longer	(43,637)	(6,677)
Total	$ (43,637)	$ (8,523)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	0	4
12 months or longer | Position	16	12
Total | Position	16	16
State & Municipal [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 19,439	$ 87,515
12 months or longer	64,376	0
Total	83,815	87,515
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(2,716)	(1,559)
12 months or longer	(11,595)	0
Total	$ (14,311)	$ (1,559)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	16	61
12 months or longer | Position	52	0
Total | Position	68	61
Mortgage-Backed [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 245,801	$ 281,217
12 months or longer	236,256	39,491
Total	482,057	320,708
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(22,675)	(4,319)
12 months or longer	(45,684)	(1,525)
Total	$ (68,359)	$ (5,844)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	160	24
12 months or longer | Position	24	6
Total | Position	184	30
Collateralized Mortgage Obligations [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 381,916	$ 341,673
12 months or longer	223,569	15,774
Total	605,485	357,447
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(37,494)	(5,495)
12 months or longer	(40,671)	(502)
Total	$ (78,165)	$ (5,997)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	96	34
12 months or longer | Position	26	4
Total | Position	122	38
Corporate [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 53,379	$ 9,987
12 months or longer	0	0
Total	53,379	9,987
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(5,601)	(13)
12 months or longer	0	0
Total	$ (5,601)	$ (13)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	17	2
12 months or longer | Position	0	0
Total | Position	17	2