Securities (Securities Available for Sale) (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	$ 16,602,158	$ 17,965,338
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	4,845	14,828
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	1,563,378	1,401,795
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale	15,043,625	16,578,371
US Treasury [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	3,692,215	5,212,894
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	0	0
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	249,895	285,305
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale	3,442,320	4,927,589
Residential Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	8,024,704	7,463,954
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	2,352	9,066
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	1,029,154	876,338
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale	6,997,902	6,596,682
States and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	4,842,060	5,245,721
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	2,493	5,762
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	284,329	240,152
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale	4,560,224	5,011,331
Other [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	43,179	42,769
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	0	0
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	0	0
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale	$ 43,179	$ 42,769