CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Interest income
Interest and fees on loans	$ 285,698	$ 274,100
Mortgage loans held-for-sale	6,087	9,036
Interest-bearing deposits with banks	1,687	1,199
Federal funds sold and securities purchased under resale agreements	431	0
Investment securities	32,398	19,264
Trading account securities	5	2
Federal Home Loan Bank and Federal Reserve Bank stock	1,772	1,745
Brokerage customer receivables	174	123
Total interest income	328,252	305,469
Interest expense
Interest on deposits	14,854	27,944
Interest on Federal Home Loan Bank advances	4,816	4,840
Interest on other borrowings	2,239	2,609
Interest on subordinated notes	5,482	5,477
Interest on junior subordinated debentures	1,567	2,704
Total interest expense	28,958	43,574
Net interest income	299,294	261,895
Provision for credit losses	4,106	(45,347)
Net interest income after provision for credit losses	295,188	307,242
Non-interest income
Revenue from contracts with customers	54,552	47,768
Mortgage banking	77,231	113,494
(Losses) gains on investment securities, net	(2,782)	1,154
Fees from covered call options	3,742	0
Trading gains, net	3,889	419
Operating lease income, net	15,475	14,440
Other	18,558	15,654
Total non-interest income	162,790	186,506
Non-interest expense
Salaries and employee benefits	172,355	180,809
Software and equipment	22,810	20,912
Operating lease equipment depreciation	9,708	10,771
Occupancy, net	17,824	19,996
Data processing	7,505	6,048
Advertising and marketing	11,924	8,546
Professional fees	8,401	7,587
Amortization of other acquisition-related intangible assets	1,609	2,007
FDIC insurance	7,729	6,558
Other real estate owned expense, net	(1,032)	(251)
Other	25,465	23,906
Total non-interest expense	284,298	286,889
Income before taxes	173,680	206,859
Income tax expense	46,289	53,711
Net income	127,391	153,148
Preferred stock dividends	6,991	6,991
Net income applicable to common shares	$ 120,400	$ 146,157
Net income per common share-Basic (usd per share)	$ 2.11	$ 2.57
Net income per common share-Diluted (usd per share)	2.07	2.54
Cash dividends declared per common share (usd per share)	$ 0.34	$ 0.31
Weighted average common shares outstanding (in shares)	57,196	56,904
Dilutive potential common shares (in shares)	862	681
Average common shares and dilutive common shares (in shares)	58,058	57,585
Wealth management
Non-interest income
Revenue from contracts with customers	$ 31,394	$ 29,309
Service charges on deposit accounts
Non-interest income
Revenue from contracts with customers	$ 15,283	$ 12,036