Investment Securities Gross Unrealized Losses and Fair Values of Investments by Category and Length of Time in a Continuous Unrealized Loss Position (Details) $ in Thousands	Jun. 30, 2023 USD ($) Security	Dec. 31, 2022 USD ($) Security
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | Security	256	719
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 453,525	$ 2,108,595
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (24,621)	$ (256,382)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | Security	518	63
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 2,087,259	$ 477,373
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(319,524)	(89,665)
Debt Securities, Available-for-sale, Unrealized Loss Position	2,540,784	2,585,968
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (344,145)	$ (346,047)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | Security	117	127
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 459,227	$ 504,922
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (37,299)	$ (38,304)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | Security	63	53
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	$ 627,465	$ 620,127
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	(170,622)	(157,903)
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	1,086,692	1,125,049
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	$ (207,921)	$ (196,207)
US Government Debt Securities
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | Security	0	1
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 0	$ 96,906
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ 0	$ (2,814)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | Security	3	2
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 220,638	$ 121,579
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(4,904)	(4,841)
Debt Securities, Available-for-sale, Unrealized Loss Position	220,638	218,485
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (4,904)	$ (7,655)
US Government Agencies Debt Securities
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | Security	1	1
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 999	$ 1,008
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (45)	$ (42)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | Security	0	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 0	$ 0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Debt Securities, Available-for-sale, Unrealized Loss Position	999	1,008
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (45)	$ (42)
State and Municipal Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | Security	72	360
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 156,269	$ 995,122
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (3,092)	$ (157,397)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | Security	302	29
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 869,492	$ 61,089
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(149,354)	(21,419)
Debt Securities, Available-for-sale, Unrealized Loss Position	1,025,761	1,056,211
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (152,446)	$ (178,816)
Corporate Debt Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | Security	29	66
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 132,631	$ 376,398
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (11,734)	$ (31,333)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | Security	42	6
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 288,993	$ 37,157
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(38,840)	(6,150)
Debt Securities, Available-for-sale, Unrealized Loss Position	421,624	413,555
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (50,574)	$ (37,483)
Collateralized Mortgage Obligations [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | Security	27	96
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 19,500	$ 113,191
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (1,543)	$ (7,650)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | Security	67	1
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 100,958	$ 20,842
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(12,233)	(5,472)
Debt Securities, Available-for-sale, Unrealized Loss Position	120,458	134,033
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (13,776)	$ (13,122)
Residential Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | Security	66	81
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 57,495	$ 154,861
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (3,864)	$ (18,301)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | Security	29	5
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 146,358	$ 55,293
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(25,059)	(11,546)
Debt Securities, Available-for-sale, Unrealized Loss Position	203,853	210,154
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (28,923)	$ (29,847)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | Security	99	106
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 221,910	$ 246,667
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (14,592)	$ (14,275)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | Security	21	14
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	$ 153,680	$ 153,178
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	(41,522)	(43,205)
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	375,590	399,845
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	$ (56,114)	$ (57,480)
Commercial Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | Security	61	114
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 86,631	$ 371,109
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (4,343)	$ (38,845)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | Security	75	20
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 460,820	$ 181,413
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	(89,134)	(40,237)
Debt Securities, Available-for-sale, Unrealized Loss Position	547,451	552,522
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (93,477)	$ (79,082)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | Security	18	21
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 237,317	$ 258,255
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (22,707)	$ (24,029)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | Security	42	39
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	$ 473,785	$ 466,949
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	(129,100)	(114,698)
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	711,102	725,204
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	$ (151,807)	$ (138,727)