Securities - Gross Unrealized Losses and Fair Value by Investment Category (Details) $ in Thousands	Dec. 31, 2022 USD ($) security	Dec. 31, 2021 USD ($) security
Available for Sale:
Number of positions, Less than 12 Months | security	247	121
Fair Value, Less than 12 Months	$ 726,431	$ 1,899,384
Unrealized Losses, Less than 12 Months	$ (41,924)	$ (30,120)
Number of positions, 12 Months or More | security	98	7
Fair Value, 12 Months or More	$ 788,657	$ 25,634
Unrealized Losses, 12 Months or More	$ (159,375)	$ (904)
Number of positions | security	345	128
Fair Value	$ 1,515,088	$ 1,925,018
Unrealized Losses	$ (201,299)	$ (31,024)
Held to Maturity:
Number of positions, Less than 12 Months | security	122	90
Fair Value, Less than 12 Months	$ 448,575	$ 201,791
Unrealized Losses, Less than 12 Months	$ (51,435)	$ (1,154)
Number of positions, 12 Months or More | security	115	1
Fair Value, 12 Months or More	$ 755,527	$ 5,354
Unrealized Losses, 12 Months or More	$ (66,112)	$ (17)
Number of positions | security	237	91
Fair Value	$ 1,204,102	$ 207,145
Unrealized Losses	$ (117,547)	$ (1,171)
Obligations of other U.S. Government agencies and corporations
Available for Sale:
Number of positions, Less than 12 Months | security	5
Fair Value, Less than 12 Months	$ 164,660
Unrealized Losses, Less than 12 Months	$ (5,340)
Number of positions, 12 Months or More | security	0
Fair Value, 12 Months or More	$ 0
Unrealized Losses, 12 Months or More	$ 0
Number of positions | security	5
Fair Value	$ 164,660
Unrealized Losses	$ (5,340)
Obligations of states and political subdivisions
Available for Sale:
Number of positions, Less than 12 Months | security	84	8
Fair Value, Less than 12 Months	$ 96,939	$ 34,303
Unrealized Losses, Less than 12 Months	$ (4,869)	$ (216)
Number of positions, 12 Months or More | security	11	3
Fair Value, 12 Months or More	$ 33,038	$ 3,892
Unrealized Losses, 12 Months or More	$ (4,499)	$ (53)
Number of positions | security	95	11
Fair Value	$ 129,977	$ 38,195
Unrealized Losses	$ (9,368)	$ (269)
Held to Maturity:
Number of positions, Less than 12 Months | security	105	24
Fair Value, Less than 12 Months	$ 191,442	$ 62,131
Unrealized Losses, Less than 12 Months	$ (35,870)	$ (685)
Number of positions, 12 Months or More | security	24	0
Fair Value, 12 Months or More	$ 49,697	$ 0
Unrealized Losses, 12 Months or More	$ (12,454)	$ 0
Number of positions | security	129	24
Fair Value	$ 241,139	$ 62,131
Unrealized Losses	$ (48,324)	$ (685)
Other debt securities
Available for Sale:
Number of positions, Less than 12 Months | security	25	1
Fair Value, Less than 12 Months	$ 63,423	$ 8,699
Unrealized Losses, Less than 12 Months	$ (3,167)	$ (148)
Number of positions, 12 Months or More | security	1	0
Fair Value, 12 Months or More	$ 7,412	$ 0
Unrealized Losses, 12 Months or More	$ (883)	$ 0
Number of positions | security	26	1
Fair Value	$ 70,835	$ 8,699
Unrealized Losses	$ (4,050)	$ (148)
Held to Maturity:
Number of positions, Less than 12 Months | security	2	8
Fair Value, Less than 12 Months	$ 42,567	$ 21,972
Unrealized Losses, Less than 12 Months	$ (2,013)	$ (79)
Number of positions, 12 Months or More | security	8	0
Fair Value, 12 Months or More	$ 16,042	$ 0
Unrealized Losses, 12 Months or More	$ (2,253)	$ 0
Number of positions | security	10	8
Fair Value	$ 58,609	$ 21,972
Unrealized Losses	$ (4,266)	$ (79)
Government agency mortgage backed securities | Residential mortgage backed securities:
Available for Sale:
Number of positions, Less than 12 Months | security	97	41
Fair Value, Less than 12 Months	$ 214,516	$ 727,546
Unrealized Losses, Less than 12 Months	$ (15,115)	$ (6,312)
Number of positions, 12 Months or More | security	29	1
Fair Value, 12 Months or More	$ 237,970	$ 12,305
Unrealized Losses, 12 Months or More	$ (36,921)	$ (504)
Number of positions | security	126	42
Fair Value	$ 452,486	$ 739,851
Unrealized Losses	$ (52,036)	$ (6,816)
Held to Maturity:
Number of positions, Less than 12 Months | security	8	50
Fair Value, Less than 12 Months	$ 94,258	$ 53,560
Unrealized Losses, Less than 12 Months	$ (4,186)	$ (181)
Number of positions, 12 Months or More | security	62	1
Fair Value, 12 Months or More	$ 364,870	$ 5,354
Unrealized Losses, 12 Months or More	$ (20,246)	$ (17)
Number of positions | security	70	51
Fair Value	$ 459,128	$ 58,914
Unrealized Losses	$ (24,432)	$ (198)
Government agency mortgage backed securities | Commercial mortgage backed securities:
Available for Sale:
Number of positions, Less than 12 Months | security	4	1
Fair Value, Less than 12 Months	$ 10,114	$ 1,791
Unrealized Losses, Less than 12 Months	$ (1,053)	$ (1)
Number of positions, 12 Months or More | security	0	1
Fair Value, 12 Months or More	$ 0	$ 432
Unrealized Losses, 12 Months or More	$ 0	$ 0
Number of positions | security	4	2
Fair Value	$ 10,114	$ 2,223
Unrealized Losses	$ (1,053)	$ (1)
Held to Maturity:
Number of positions, Less than 12 Months | security	1
Fair Value, Less than 12 Months	$ 13,745
Unrealized Losses, Less than 12 Months	$ (3,261)
Number of positions, 12 Months or More | security	0
Fair Value, 12 Months or More	$ 0
Unrealized Losses, 12 Months or More	$ 0
Number of positions | security	1
Fair Value	$ 13,745
Unrealized Losses	$ (3,261)
Government agency collateralized mortgage obligations | Residential mortgage backed securities:
Available for Sale:
Number of positions, Less than 12 Months | security	16	49
Fair Value, Less than 12 Months	$ 109,753	$ 966,126
Unrealized Losses, Less than 12 Months	$ (8,552)	$ (20,371)
Number of positions, 12 Months or More | security	36	0
Fair Value, 12 Months or More	$ 391,416	$ 0
Unrealized Losses, 12 Months or More	$ (95,312)	$ 0
Number of positions | security	52	49
Fair Value	$ 501,169	$ 966,126
Unrealized Losses	$ (103,864)	$ (20,371)
Held to Maturity:
Number of positions, Less than 12 Months | security	4	1
Fair Value, Less than 12 Months	$ 98,912	$ 24,740
Unrealized Losses, Less than 12 Months	$ (5,479)	$ (92)
Number of positions, 12 Months or More | security	14	0
Fair Value, 12 Months or More	$ 293,698	$ 0
Unrealized Losses, 12 Months or More	$ (25,227)	$ 0
Number of positions | security	18	1
Fair Value	$ 392,610	$ 24,740
Unrealized Losses	$ (30,706)	$ (92)
Government agency collateralized mortgage obligations | Commercial mortgage backed securities:
Available for Sale:
Number of positions, Less than 12 Months | security	16	21
Fair Value, Less than 12 Months	$ 67,026	$ 160,919
Unrealized Losses, Less than 12 Months	$ (3,828)	$ (3,072)
Number of positions, 12 Months or More | security	21	2
Fair Value, 12 Months or More	$ 118,821	$ 9,005
Unrealized Losses, 12 Months or More	$ (21,760)	$ (347)
Number of positions | security	37	23
Fair Value	$ 185,847	$ 169,924
Unrealized Losses	$ (25,588)	$ (3,419)
Held to Maturity:
Number of positions, Less than 12 Months | security	2	7
Fair Value, Less than 12 Months	$ 7,651	$ 39,388
Unrealized Losses, Less than 12 Months	$ (626)	$ (117)
Number of positions, 12 Months or More | security	7	0
Fair Value, 12 Months or More	$ 31,220	$ 0
Unrealized Losses, 12 Months or More	$ (5,932)	$ 0
Number of positions | security	9	7
Fair Value	$ 38,871	$ 39,388
Unrealized Losses	$ (6,558)	$ (117)