Securities (Securities Available for Sale) (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	$ 17,013,723	$ 16,602,158
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	83,690	4,845
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	1,126,817	1,563,378
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale	15,970,596	15,043,625
US Treasury [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	2,604,852	3,692,215
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	22	0
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	148,357	249,895
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale	2,456,517	3,442,320
Residential Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	8,818,139	8,024,704
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	54,668	2,352
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	751,013	1,029,154
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale	8,121,794	6,997,902
States and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	5,548,304	4,842,060
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	29,000	2,493
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	227,447	284,329
Debt Securities, Available-for-sale, Allowance for Credit Loss	0	0
Debt Securities, Available-for-sale	5,349,857	4,560,224
Other [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	42,428	43,179
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	$ 42,428	$ 43,179