Fair Value Measurements (Estimated Fair Values of Financial Instruments) (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Held to maturity securities	$ 2,684,779	$ 2,852,495
Loans held for sale	13,269	10,843
Derivative financial instruments	84,458	110,734
Derivative Liability	87,567	32,601
Total Fair Value [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, interest-bearing bank deposits, and federal funds sold	1,188,284	888,519
Available for sale securities	4,915,195	5,556,041
Held to maturity securities	2,485,918	2,615,398
Loans, net	23,186,259	22,137,375
Loans held for sale	26,124	26,385
Derivative financial instruments	90,712	109,497
Deposits	29,679,228	29,041,635
Federal funds purchased	350	1,850
Securities sold under agreements to repurchase	454,479	444,421
Short-term FHLB Borrowings	700,000	1,425,000
Long-term debt	196,182	200,060
Derivative Liability	207,138	204,121
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	1,188,284	888,519
Federal funds purchased	350	1,850
Securities sold under agreements to repurchase	454,479	444,421
Short-term FHLB Borrowings	700,000	1,425,000
Total Fair Value [Member] | Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Available for sale securities	4,915,195	5,556,041
Held to maturity securities	2,485,918	2,615,398
Loans, net	15,882	4,692
Loans held for sale	26,124	26,385
Derivative financial instruments	90,712	109,497
Long-term debt	196,182	200,060
Derivative Liability	205,796	202,238
Total Fair Value [Member] | Level 3 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Loans, net	23,170,377	22,132,683
Deposits	29,679,228	29,041,635
Derivative Liability	1,342	1,883
Carrying Amount [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash, interest-bearing bank deposits, and federal funds sold	1,188,284	888,519
Available for sale securities	4,915,195	5,556,041
Held to maturity securities	2,684,779	2,852,495
Loans, net	23,614,010	22,806,257
Loans held for sale	26,124	26,385
Derivative financial instruments	90,712	109,497
Deposits	29,690,059	29,070,349
Federal funds purchased	350	1,850
Securities sold under agreements to repurchase	454,479	444,421
Short-term FHLB Borrowings	700,000	1,425,000
Long-term debt	236,317	242,077
Derivative Liability	$ 207,138	$ 204,121