Securities Available for Sale and Held to Maturity - Securities with Gross Unrealized Losses, Segregated by Length of Impairment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	$ 2,423,465	$ 355,939
Estimated Fair Value, 12 Months or More	67,875	12,493
Estimated Fair Value, Total	2,491,340	368,432
Gross Unrealized (Losses), Less than 12 Months	(29,552)	(1,412)
Gross Unrealized (Losses), 12 Months or More	(1,406)	(493)
Gross Unrealized (Losses), Total	(30,958)	(1,905)
US Treasury Securities [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	315,123
Estimated Fair Value, Total	315,123
Gross Unrealized (Losses), Less than 12 Months	(4,938)
Gross Unrealized (Losses), Total	(4,938)
U.S. Government Agency Obligations [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	1,312	0
Estimated Fair Value, 12 Months or More	8,619	11,167
Estimated Fair Value, Total	9,931	11,167
Gross Unrealized (Losses), Less than 12 Months	(5)	0
Gross Unrealized (Losses), 12 Months or More	(332)	(481)
Gross Unrealized (Losses), Total	(337)	(481)
Obligations of States and Political Subdivisions [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	3,006	0
Estimated Fair Value, 12 Months or More	667	667
Estimated Fair Value, Total	3,673	667
Gross Unrealized (Losses), Less than 12 Months	(1)	0
Gross Unrealized (Losses), 12 Months or More	(2)	(3)
Gross Unrealized (Losses), Total	(3)	(3)
Residential Mortgage Pass-Through Securities Guaranteed by GNMA [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	6,040	1,636
Estimated Fair Value, 12 Months or More	0	0
Estimated Fair Value, Total	6,040	1,636
Gross Unrealized (Losses), Less than 12 Months	(37)	(3)
Gross Unrealized (Losses), 12 Months or More	0	0
Gross Unrealized (Losses), Total	(37)	(3)
Residential Mortgage Pass-Through Securities Issued by FNMA and FHLMC [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	1,734,921	324,905
Estimated Fair Value, 12 Months or More	55,303	0
Estimated Fair Value, Total	1,790,224	324,905
Gross Unrealized (Losses), Less than 12 Months	(19,980)	(1,308)
Gross Unrealized (Losses), 12 Months or More	(1,034)	0
Gross Unrealized (Losses), Total	(21,014)	(1,308)
Other Residential Mortgage-Backed Securities Issued or Guaranteed by FNMA, FHLMC or GNMA [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	19,038	29,398
Estimated Fair Value, 12 Months or More	2,647	0
Estimated Fair Value, Total	21,685	29,398
Gross Unrealized (Losses), Less than 12 Months	(99)	(101)
Gross Unrealized (Losses), 12 Months or More	(29)	0
Gross Unrealized (Losses), Total	(128)	(101)
Commercial Mortgage-Backed Securities Issued or Guaranteed by FNMA, FHLMC or GNMA [Member]
Schedule of Available For Sale and Held to Maturity Securities [Line Items]
Estimated Fair Value, Less than 12 Months	344,025	0
Estimated Fair Value, 12 Months or More	639	659
Estimated Fair Value, Total	344,664	659
Gross Unrealized (Losses), Less than 12 Months	(4,492)	0
Gross Unrealized (Losses), 12 Months or More	(9)	(9)
Gross Unrealized (Losses), Total	$ (4,501)	$ (9)