Securities, AFS Securities in Continuous Unrealized Loss Position (Details) $ in Thousands	Mar. 31, 2023 USD ($) Position	Dec. 31, 2022 USD ($) Position
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 121,858	$ 509,788
12 months or longer	1,385,108	1,012,964
Total	1,506,966	1,522,752
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(3,718)	(36,681)
12 months or longer	(192,273)	(180,014)
Total	$ (195,991)	$ (216,695)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	62	245
12 months or longer | Position	332	170
Total | Position	394	415
AIR on AFS debt securities	$ 4,100	$ 4,200
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Other Assets	Other Assets
U.S. Treasury [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 9,818	$ 55,616
12 months or longer	113,761	66,042
Total	123,579	121,658
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(114)	(3,864)
12 months or longer	(9,185)	(7,369)
Total	$ (9,299)	$ (11,233)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	1	5
12 months or longer | Position	7	3
Total | Position	8	8
Federal Agency [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 0	$ 0
12 months or longer	210,220	206,419
Total	210,220	206,419
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	0	0
12 months or longer	(38,190)	(42,000)
Total	$ (38,190)	$ (42,000)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	0	0
12 months or longer | Position	16	16
Total | Position	16	16
State & Municipal [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 1,454	$ 3,679
12 months or longer	82,792	78,395
Total	84,246	82,074
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(51)	(341)
12 months or longer	(11,774)	(13,849)
Total	$ (11,825)	$ (14,190)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	1	2
12 months or longer | Position	65	64
Total | Position	66	66
Mortgage-Backed [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 22,278	$ 204,447
12 months or longer	440,057	267,926
Total	462,335	472,373
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(736)	(15,048)
12 months or longer	(54,485)	(47,303)
Total	$ (55,221)	$ (62,351)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	33	149
12 months or longer | Position	134	32
Total | Position	167	181
Collateralized Mortgage Obligations [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 74,631	$ 211,612
12 months or longer	504,718	374,376
Total	579,349	585,988
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(2,080)	(14,458)
12 months or longer	(71,199)	(66,299)
Total	$ (73,279)	$ (80,757)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	23	77
12 months or longer | Position	97	49
Total | Position	120	126
Corporate [Member]
Unrealized Loss Position, Fair Value [Abstract]
Less than 12 months	$ 13,677	$ 34,434
12 months or longer	33,560	19,806
Total	47,237	54,240
Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 months	(737)	(2,970)
12 months or longer	(7,440)	(3,194)
Total	$ (8,177)	$ (6,164)
Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months | Position	4	12
12 months or longer | Position	13	6
Total | Position	17	18