Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Assets [Abstract]
Cash and due from banks	$ 897,811	$ 947,613
Interest-bearing cash and cash equivalents	178,352	400,652
Trading securities	5,212,791	5,193,505
Investment securities, net of allowance	2,128,881	2,244,153
Available for sale securities	12,793,784	12,286,681
Fair value option securities	19,050	20,671
Restricted equity securities	475,209	423,099
Residential mortgage loans held for sale	107,465	56,935
Loans	24,553,581	23,904,968
Allowance for loan losses	(287,826)	(277,123)
Loans, net of allowance	24,265,755	23,627,845
Premises and equipment, net	632,388	622,223
Receivables	334,019	317,922
Goodwill	1,044,749	1,044,749
Intangible assets, net	54,028	59,979
Mortgage servicing rights	333,246	293,884
Real estate and other repossessed assets, net of allowance	2,334	2,875
Derivative contracts, net	225,076	410,304
Cash surrender value of bank-owned life insurance	412,278	409,548
Receivable on unsettled securities sales	14,673	391,910
Other assets	1,271,568	1,070,282
Total assets	50,403,457	49,824,830
Deposits [Abstract]
Non-interest bearing demand deposits	8,840,178	9,196,493
Interest-bearing deposits: [Abstract]
Transaction	23,107,042	20,964,101
Savings	830,489	847,085
Time	3,463,935	3,012,022
Total deposits	36,241,644	34,019,701
Funds purchased and repurchase agreements	813,758	1,122,748
Other borrowings	6,528,538	7,701,552
Subordinated debentures	131,156	131,150
Accrued interest, taxes and expense	305,839	338,996
Derivative contracts, net	287,509	587,473
Due on unsettled securities purchases	347,663	254,057
Other liabilities	515,380	523,734
Total liabilities	45,171,487	44,679,411
Shareholders' equity: [Abstract]
Common stock	5	5
Capital surplus	1,416,807	1,406,745
Retained earnings	5,387,949	5,211,512
Treasury stock	(970,129)	(876,720)
Accumulated other comprehensive income (loss)	(605,502)	(599,100)
Total shareholders' equity	5,229,130	5,142,442
Non-controlling interests	2,840	2,977
Total equity	5,231,970	5,145,419
Total liabilities and equity	$ 50,403,457	$ 49,824,830