Fair Value Measurements (Estimated Fair Values of Financial Instruments) (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Held to maturity securities	$ 2,435,663	$ 2,684,779
Loans held for sale	18,929	13,269
Derivative financial instruments, Financial assets	71,893	84,458
Derivative financial instruments, Financial liabilities	54,707	87,567
Total Fair Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, interest-bearing bank deposits, and federal funds sold	1,514,625	1,188,284
Available for sale securities	5,161,491	4,915,195
Held to maturity securities	2,233,526	2,485,918
Loans, net	22,562,577	23,186,259
Loans held for sale	21,525	26,124
Derivative financial instruments, Financial assets	73,840	90,712
Deposits	29,482,628	29,679,228
Federal funds purchased	300	350
Securities sold under agreements to repurchase	638,715	454,479
Short-term FHLB Borrowings		700,000
Long-term debt	174,660	196,182
Derivative financial instruments, Financial liabilities	160,623	207,138
Total Fair Value [Member] | Level 1 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, interest-bearing bank deposits, and federal funds sold	1,514,216	1,188,284
Federal funds purchased		350
Securities sold under agreements to repurchase		454,479
Short-term FHLB Borrowings		700,000
Total Fair Value [Member] | Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, interest-bearing bank deposits, and federal funds sold	409
Available for sale securities	5,161,491	4,915,195
Held to maturity securities	2,233,526	2,485,918
Loans, net		15,882
Loans held for sale	21,525	26,124
Derivative financial instruments, Financial assets	73,840	90,712
Federal funds purchased	300
Securities sold under agreements to repurchase	638,715
Long-term debt	174,660	196,182
Derivative financial instruments, Financial liabilities	158,534	205,796
Total Fair Value [Member] | Level 3 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Loans, net	22,562,577	23,170,377
Deposits	29,482,628	29,679,228
Derivative financial instruments, Financial liabilities	2,089	1,342
Carrying Amount [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, interest-bearing bank deposits, and federal funds sold	1,514,625	1,188,284
Available for sale securities	5,161,491	4,915,195
Held to maturity securities	2,435,663	2,684,779
Loans, net	22,980,565	23,614,010
Loans held for sale	21,525	26,124
Derivative financial instruments, Financial assets	73,840	90,712
Deposits	29,492,851	29,690,059
Federal funds purchased	300	350
Securities sold under agreements to repurchase	638,715	454,479
Short-term FHLB Borrowings		700,000
Long-term debt	210,544	236,317
Derivative financial instruments, Financial liabilities	$ 160,623	$ 207,138