Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Interest income:
Loans	$ 1,520,021	$ 1,599,165	$ 1,358,480
Investment securities:
Taxable	634,992	568,851	541,605
Non-taxable	61,055	44,952	34,616
Federal funds sold, securities purchased under agreements to resell and other short-term investment securities	25,542	96,440	35,208
Total interest income	2,241,610	2,309,408	1,969,909
Interest expense:
Deposits	60,219	177,672	29,306
Borrowings	25,107	35,135	46,615
Total interest expense	85,326	212,807	75,921
Net interest income	2,156,284	2,096,601	1,893,988
Provision for credit losses	219,510	106,416	87,870
Net interest income after provision for credit losses	1,936,774	1,990,185	1,806,118
Noninterest income:
Gains on investment securities, net	420,752	134,670	88,094
Gains on equity warrant assets, net	237,428	138,078	89,142
Client investment fees	132,200	182,068	130,360
Foreign exchange fees	178,733	159,262	138,812
Credit card fees	97,737	118,719	94,072
Deposit service charges	90,336	89,200	76,097
Lending related fees	57,533	49,920	41,949
Letters of credit and standby letters of credit fees	46,659	42,669	34,600
Investment banking revenue	413,985	195,177	0
Commissions	66,640	56,346	0
Other	98,145	55,370	51,858
Noninterest income	1,840,148	1,221,479	744,984
Noninterest expense:
Compensation and benefits	1,318,457	989,734	726,980
Professional services	247,084	205,479	158,835
Premises and equipment	127,125	96,770	77,918
Net occupancy	100,889	69,279	54,753
Business development and travel	23,724	68,912	48,180
FDIC and state assessments	27,587	18,509	34,276
Other	190,175	152,579	87,251
Total noninterest expense	2,035,041	1,601,262	1,188,193
Income before income tax expense	1,741,881	1,610,402	1,362,909
Income tax expense	447,587	425,685	351,561
Net income before noncontrolling interests	1,294,294	1,184,717	1,011,348
Net income attributable to noncontrolling interests	(85,926)	(47,861)	(37,508)
Preferred stock dividends	(17,151)	0	0
Net income available to common stockholders	$ 1,191,217	$ 1,136,856	$ 973,840
Earnings per common share—basic (usd per share)	$ 23.05	$ 21.90	$ 18.35
Earnings per common share—diluted (usd per share)	$ 22.87	$ 21.73	$ 18.11