Investment Securities - Schedule of AFS Debt Securities in an Unrealized Loss Position (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	$ 2,431,795	$ 2,808,862
Less Than 12 Months, Gross Unrealized Losses	(230,904)	(56,121)
12 Months or Longer, Fair Value	1,376,637	317,559
12 Months or Longer, Gross Unrealized Losses	(228,171)	(10,167)
Total Fair Value	3,808,432	3,126,421
Total Gross Unrealized Losses	(459,075)	(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	146,219	51,455
Less Than 12 Months, Gross Unrealized Losses	(10,637)	(195)
12 Months or Longer, Fair Value	6,682	9,995
12 Months or Longer, Gross Unrealized Losses	(52)	(89)
Total Fair Value	152,901	61,450
Total Gross Unrealized Losses	(10,689)	(284)
Debt Securities Issued by States and Political Subdivisions
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	64,952	643
Less Than 12 Months, Gross Unrealized Losses	(8,859)	(5)
Total Fair Value	64,952	643
Total Gross Unrealized Losses	(8,859)	(5)
Debt Securities Issued by Government-Sponsored Enterprises
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	1,614	814
Less Than 12 Months, Gross Unrealized Losses	(79)	(10)
12 Months or Longer, Fair Value	60	49
12 Months or Longer, Gross Unrealized Losses	(6)	(1)
Total Fair Value	1,674	863
Total Gross Unrealized Losses	(85)	(11)
Debt Securities Issued by Corporations
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	278,163	249,629
Less Than 12 Months, Gross Unrealized Losses	(38,854)	(2,846)
12 Months or Longer, Fair Value	106,156	64,029
12 Months or Longer, Gross Unrealized Losses	(8,843)	(970)
Total Fair Value	384,319	313,658
Total Gross Unrealized Losses	(47,697)	(3,816)
Residential - Government Agencies
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	849,208	810,157
Less Than 12 Months, Gross Unrealized Losses	(61,865)	(17,131)
12 Months or Longer, Fair Value	342,358	41,471
12 Months or Longer, Gross Unrealized Losses	(60,881)	(1,635)
Total Fair Value	1,191,566	851,628
Total Gross Unrealized Losses	(122,746)	(18,766)
Residential - U.S. Government-Sponsored Enterprises
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	946,822	1,670,500
Less Than 12 Months, Gross Unrealized Losses	(99,484)	(35,711)
12 Months or Longer, Fair Value	902,647	180,205
12 Months or Longer, Gross Unrealized Losses	(155,058)	(6,536)
Total Fair Value	1,849,469	1,850,705
Total Gross Unrealized Losses	(254,542)	(42,247)
Commercial - Government Agencies or Sponsored Agencies
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	144,817	25,664
Less Than 12 Months, Gross Unrealized Losses	(11,126)	(223)
12 Months or Longer, Fair Value	18,734	21,810
12 Months or Longer, Gross Unrealized Losses	(3,331)	(936)
Total Fair Value	163,551	47,474
Total Gross Unrealized Losses	(14,457)	(1,159)
Mortgage-Backed Securities
Schedule Of Available For Sale Securities [Line Items]
Less Than 12 Months, Fair Value	1,940,847	2,506,321
Less Than 12 Months, Gross Unrealized Losses	(172,475)	(53,065)
12 Months or Longer, Fair Value	1,263,739	243,486
12 Months or Longer, Gross Unrealized Losses	(219,270)	(9,107)
Total Fair Value	3,204,586	2,749,807
Total Gross Unrealized Losses	$ (391,745)	$ (62,172)