Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets [Abstract]
Cash and due from banks	$ 712,067	$ 798,757
Interest-bearing cash and cash equivalents	2,125,343	381,816
Trading securities	9,136,813	4,707,975
Investment securities	210,444	244,843
Available for sale securities	13,157,817	13,050,665
Fair value option securities	43,770	114,982
Restricted equity securities	83,113	171,391
Residential mortgage loans held for sale	192,295	252,316
Loans	20,205,680	23,007,520
Allowance for loan losses	(256,421)	(388,640)
Loans, net of allowance	19,949,259	22,618,880
Premises and equipment, net	574,148	551,308
Receivables	223,021	245,880
Goodwill	1,044,749	1,048,091
Intangible assets, net	91,778	113,436
Mortgage servicing rights	163,198	101,172
Real estate and other repossessed assets, net of allowance	24,589	90,526
Derivative contracts, net	1,097,297	810,688
Cash surrender value of bank-owned life insurance	405,607	398,758
Receivable on unsettled securities sales	56,172	62,386
Other assets	957,951	907,218
Total assets	50,249,431	46,671,088
Deposits [Abstract]
Noninterest-bearing demand deposits	15,344,423	12,266,338
Interest-bearing Deposit Liabilities [Abstract]
Transaction	23,268,573	21,158,422
Savings	924,735	751,992
Time	1,704,328	1,967,128
Total deposits	41,242,059	36,143,880
Funds purchased and repurchase agreements	2,326,449	1,662,386
Other borrowings	36,753	1,882,970
Subordinated debentures	131,226	276,005
Accrued interest, taxes and expense	273,041	323,667
Derivative contracts, net	275,625	405,779
Due on unsettled securities purchases	160,686	257,627
Other liabilities	435,221	427,213
Total liabilities	44,881,060	41,379,527
Shareholders' equity: [Abstract]
Common stock	5	5
Capital surplus	1,378,794	1,368,062
Retained earnings	4,447,691	3,973,675
Treasury stock	(535,129)	(411,344)
Accumulated other comprehensive income (loss)	72,371	335,868
Total shareholders’ equity	5,363,732	5,266,266
Non-controlling interests	4,639	25,295
Total equity	5,368,371	5,291,561
Total liabilities and equity	$ 50,249,431	$ 46,671,088