Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Assets [Abstract]
Cash and due from banks	$ 804,110	$ 712,067
Interest-bearing cash and cash equivalents	804,799	2,125,343
Trading securities	2,194,618	9,136,813
Investment securities, net of allowance	2,572,360	210,444
Available for sale securities	10,040,894	13,157,817
Fair value option securities	33,966	43,770
Restricted equity securities	100,356	83,113
Residential mortgage loans held for sale	148,121	192,295
Loans	21,790,457	20,205,680
Allowance for loan losses	(241,768)	(256,421)
Loans, net of allowance	21,548,689	19,949,259
Premises and equipment, net	569,379	574,148
Receivables	200,343	223,021
Goodwill	1,044,749	1,044,749
Intangible assets, net	79,833	91,778
Mortgage servicing rights	283,806	163,198
Real estate and other repossessed assets, net of allowance	29,676	24,589
Derivative contracts, net	1,693,742	1,097,297
Cash surrender value of bank-owned life insurance	407,722	405,607
Receivable on unsettled securities sales	49,089	56,172
Other assets	1,039,194	957,951
Total assets	43,645,446	50,249,431
Deposits [Abstract]
Noninterest-bearing demand deposits	14,985,115	15,344,423
Interest-bearing deposits: [Abstract]
Transaction	19,000,023	23,268,573
Savings	971,634	924,735
Time	1,459,143	1,704,328
Total deposits	36,415,915	41,242,059
Funds purchased and repurchase agreements	626,952	2,326,449
Other borrowings	234,933	36,753
Subordinated debentures	131,168	131,226
Accrued interest, taxes and expense	212,342	273,041
Derivative contracts, net	821,275	275,625
Due on unsettled securities purchases	205,388	160,686
Other liabilities	483,165	435,221
Total liabilities	39,131,138	44,881,060
Shareholders' equity: [Abstract]
Common stock	5	5
Capital surplus	1,385,481	1,378,794
Retained earnings	4,691,924	4,447,691
Treasury stock	(662,531)	(535,129)
Accumulated other comprehensive income (loss)	(904,945)	72,371
Total shareholders’ equity	4,509,934	5,363,732
Non-controlling interests	4,374	4,639
Total equity	4,514,308	5,368,371
Total liabilities and equity	$ 43,645,446	$ 50,249,431