Consolidated Statement of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Interest income
Loans and leases, including fees	$ 5,237,405	$ 3,748,988	$ 3,975,053
Investment securities
Fully taxable	447,646	141,046	176,469
Exempt from federal taxes	51,113	116	183
Deposits at banks	509,030	47,491	32,956
Other	1,926	1,143	8,051
Total interest income	6,247,120	3,938,784	4,192,712
Interest expense
Savings and interest-checking deposits	270,765	32,998	146,701
Time deposits	23,867	18,635	66,280
Deposits at Cayman Islands office		201	4,054
Short-term borrowings	19,426	7	28
Long-term borrowings	111,106	62,165	109,332
Total interest expense	425,164	114,006	326,395
Net interest income	5,821,956	3,824,778	3,866,317
Provision for credit losses	517,000	(75,000)	800,000
Net interest income after provision for credit losses	5,304,956	3,899,778	3,066,317
Other income
Brokerage services income	87,877	62,791	47,428
Trading account and non-hedging derivative gains	26,786	24,376	40,536
Gain (loss) on bank investment securities	(5,686)	(21,220)	(9,421)
Other revenues from operations	703,669	482,889	470,588
Total other income	2,356,603	2,166,994	2,088,444
Other expense
Salaries and employee benefits	2,787,351	2,045,677	1,950,692
Equipment and net occupancy	474,316	326,698	322,037
Outside data processing and software	376,493	291,839	258,480
FDIC assessments	90,274	69,704	53,803
Advertising and marketing	90,748	64,428	61,904
Printing, postage and supplies	55,570	36,507	39,869
Amortization of core deposit and other intangible assets	55,624	10,167	14,869
Other costs of operations	1,120,060	766,603	683,586
Total other expense	5,050,436	3,611,623	3,385,240
Income before taxes	2,611,123	2,455,149	1,769,521
Income taxes	619,460	596,403	416,369
Net income (loss)	1,991,663	1,858,746	1,353,152
Net income available to common shareholders
Basic	1,891,469	1,776,977	1,279,066
Diluted	$ 1,891,480	$ 1,776,987	$ 1,279,068
Net income per common share
Basic	$ 11.59	$ 13.81	$ 9.94
Diluted	$ 11.53	$ 13.80	$ 9.94
Mortgage Banking Revenues [Member]
Other income
Revenue from contract with customer	$ 356,636	$ 571,329	$ 566,641
Service Charges on Deposit Accounts [Member]
Other income
Revenue from contract with customer	446,604	402,113	370,788
Trust Income [Member]
Other income
Revenue from contract with customer	$ 740,717	$ 644,716	$ 601,884