Consolidated Statement of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Interest income
Loans and leases, including fees	$ 972,582	$ 1,046,821
Investment securities
Fully taxable	37,071	50,110
Exempt from federal taxes	55	75
Deposits at banks	6,874	18,966
Other	380	4,447
Total interest income	1,016,962	1,120,419
Interest expense
Savings and interest-checking deposits	11,504	78,002
Time deposits	7,010	21,872
Deposits at Cayman Islands office	185	3,419
Short-term borrowings	2	23
Long-term borrowings	16,866	40,298
Total interest expense	35,567	143,614
Net interest income	981,395	976,805
Provision for credit losses	(25,000)	250,000
Net interest income after provision for credit losses	1,006,395	726,805
Other income
Brokerage services income	13,113	13,129
Trading account and foreign exchange gains	6,284	21,016
Loss on bank investment securities	(12,282)	(20,782)
Other revenues from operations	110,930	133,176
Total other income	505,598	529,360
Other expense
Salaries and employee benefits	541,078	536,843
Equipment and net occupancy	82,471	79,640
Outside data processing and software	65,751	64,410
FDIC assessments	14,188	12,271
Advertising and marketing	14,628	22,375
Printing, postage and supplies	9,317	10,852
Amortization of core deposit and other intangible assets	2,738	3,913
Other costs of operations	189,273	176,112
Total other expense	919,444	906,416
Income before taxes	592,549	349,749
Income taxes	145,300	80,927
Net income	447,249	268,822
Net income available to common shareholders
Basic	428,091	250,701
Diluted	$ 428,093	$ 250,701
Net income per common share
Basic	$ 3.33	$ 1.93
Diluted	$ 3.33	$ 1.93
Average common shares outstanding
Basic	128,537	129,696
Diluted	128,669	129,755
Mortgage Banking Revenues [Member]
Other income
Revenue from contract with customer	$ 138,754	$ 127,909
Service Charges on Deposit Accounts [Member]
Other income
Revenue from contract with customer	92,777	106,161
Trust Income [Member]
Other income
Revenue from contract with customer	$ 156,022	$ 148,751