Investment Securities - Schedule of AFS Debt Securities in an Unrealized Loss Position (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	$ 1,351,731	$ 2,808,862
Less Than 12 Months, Gross Unrealized Losses	(144,112)	(56,121)
12 Months or Longer, Fair Value	968,071	317,559
12 Months or Longer, Gross Unrealized Losses	(184,836)	(10,167)
Total Fair Value	2,319,802	3,126,421
Total Gross Unrealized Losses	(328,948)	(66,288)
Debt Securities Issued by the U.S. Treasury and Government Agencies
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	124,896	51,455
Less Than 12 Months, Gross Unrealized Losses	(12,517)	(195)
12 Months or Longer, Fair Value	28,316	9,995
12 Months or Longer, Gross Unrealized Losses	(3,707)	(89)
Total Fair Value	153,212	61,450
Total Gross Unrealized Losses	(16,224)	(284)
Debt Securities Issued by States and Political Subdivisions
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	60,528	643
Less Than 12 Months, Gross Unrealized Losses	(12,952)	(5)
12 Months or Longer, Fair Value	434
12 Months or Longer, Gross Unrealized Losses	(43)
Total Fair Value	60,962	643
Total Gross Unrealized Losses	(12,995)	(5)
Debt Securities Issued by Government-Sponsored Enterprises
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	1,011	814
Less Than 12 Months, Gross Unrealized Losses	(72)	(10)
12 Months or Longer, Fair Value	606	49
12 Months or Longer, Gross Unrealized Losses	(68)	(1)
Total Fair Value	1,617	863
Total Gross Unrealized Losses	(140)	(11)
Debt Securities Issued by Corporations
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	125,121	249,629
Less Than 12 Months, Gross Unrealized Losses	(13,518)	(2,846)
12 Months or Longer, Fair Value	245,598	64,029
12 Months or Longer, Gross Unrealized Losses	(46,573)	(970)
Total Fair Value	370,719	313,658
Total Gross Unrealized Losses	(60,091)	(3,816)
Residential - Government Agencies
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	528,883	810,157
Less Than 12 Months, Gross Unrealized Losses	(40,230)	(17,131)
12 Months or Longer, Fair Value	235,024	41,471
12 Months or Longer, Gross Unrealized Losses	(49,307)	(1,635)
Total Fair Value	763,907	851,628
Total Gross Unrealized Losses	(89,537)	(18,766)
Residential - U.S. Government-Sponsored Enterprises
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	393,814	1,670,500
Less Than 12 Months, Gross Unrealized Losses	(51,047)	(35,711)
12 Months or Longer, Fair Value	424,086	180,205
12 Months or Longer, Gross Unrealized Losses	(78,767)	(6,536)
Total Fair Value	817,900	1,850,705
Total Gross Unrealized Losses	(129,814)	(42,247)
Commercial - Government Agencies or Sponsored Agencies
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	117,478	25,664
Less Than 12 Months, Gross Unrealized Losses	(13,776)	(223)
12 Months or Longer, Fair Value	34,007	21,810
12 Months or Longer, Gross Unrealized Losses	(6,371)	(936)
Total Fair Value	151,485	47,474
Total Gross Unrealized Losses	(20,147)	(1,159)
Mortgage-Backed Securities
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	1,040,175	2,506,321
Less Than 12 Months, Gross Unrealized Losses	(105,053)	(53,065)
12 Months or Longer, Fair Value	693,117	243,486
12 Months or Longer, Gross Unrealized Losses	(134,445)	(9,107)
Total Fair Value	1,733,292	2,749,807
Total Gross Unrealized Losses	$ (239,498)	$ (62,172)