Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Assets [Abstract]
Cash and due from banks	$ 1,313,563	$ 712,067
Interest-bearing cash and cash equivalents	723,787	2,125,343
Trading securities	2,859,444	9,136,813
Investment securities, net of allowance	2,637,345	210,444
Available for sale securities	10,152,663	13,157,817
Fair value option securities	37,927	43,770
Restricted equity securities	95,130	83,113
Residential mortgage loans held for sale	182,726	192,295
Loans and Leases Receivable, Gross	21,291,148	20,205,680
Allowance for loan losses	(241,114)	(256,421)
Loans, net of allowance	21,050,034	19,949,259
Premises and equipment, net	573,605	574,148
Receivables	176,672	223,021
Goodwill	1,044,749	1,044,749
Intangible assets, net	83,744	91,778
Mortgage servicing rights	270,312	163,198
Real estate and other repossessed assets, net of allowance	22,221	24,589
Derivative contracts, net	1,992,977	1,097,297
Cash surrender value of bank-owned life insurance	409,937	405,607
Receivable on unsettled securities sales	60,168	56,172
Other assets	1,690,068	957,951
Total assets	45,377,072	50,249,431
Deposits [Abstract]
Noninterest-bearing demand deposits	15,720,296	15,344,423
Interest-bearing deposits: [Abstract]
Transaction	20,544,199	23,268,573
Savings	984,824	924,735
Time	1,369,599	1,704,328
Total deposits	38,618,918	41,242,059
Funds purchased and repurchase agreements	677,030	2,326,449
Other borrowings	35,505	36,753
Subordinated debentures	131,223	131,226
Accrued interest, taxes and expense	211,419	273,041
Derivative contracts, net	214,576	275,625
Due on unsettled securities purchases	297,352	160,686
Other liabilities	449,507	435,221
Total liabilities	40,635,530	44,881,060
Shareholders' equity: [Abstract]
Common stock	5	5
Capital surplus	1,381,676	1,378,794
Retained earnings	4,570,837	4,447,691
Treasury stock	(612,551)	(535,129)
Accumulated other comprehensive income (loss)	(602,628)	72,371
Total shareholders’ equity	4,737,339	5,363,732
Non-controlling interests	4,203	4,639
Total equity	4,741,542	5,368,371
Total liabilities and equity	$ 45,377,072	$ 50,249,431