Consolidated Statements Of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Interest income
Interest and fees on loans	$ 274,100	$ 301,839
Mortgage loans held-for-sale	9,036	3,165
Interest-bearing deposits with banks	1,199	4,768
Federal funds sold and securities purchased under resale agreements	0	86
Investment securities	19,264	32,467
Trading account securities	2	7
Federal Home Loan Bank and Federal Reserve Bank stock	1,745	1,577
Brokerage customer receivables	123	158
Total interest income	305,469	344,067
Interest expense
Interest on deposits	27,944	67,435
Interest on Federal Home Loan Bank advances	4,840	3,360
Interest on other borrowings	2,609	3,546
Interest on subordinated notes	5,477	5,472
Interest on junior subordinated debentures	2,704	2,811
Total interest expense	43,574	82,624
Net interest income	261,895	261,443
Provision for credit losses	(45,347)	52,961
Net interest income after provision for credit losses	307,242	208,482
Non-interest income
Revenue from contracts with customers	47,768	43,655
Mortgage banking	113,494	48,326
Gains (losses) on investment securities, net	1,154	(4,359)
Fees from covered call options	0	2,292
Trading gains (losses), net	419	(451)
Operating lease income, net	14,440	11,984
Other	15,654	18,244
Total non-interest income	186,506	113,242
Non-interest expense
Salaries and employee benefits	180,809	136,762
Equipment	20,912	14,834
Operating lease equipment depreciation	10,771	9,260
Occupancy, net	19,996	17,547
Data processing	6,048	8,373
Advertising and marketing	8,546	10,862
Professional fees	7,587	6,721
Amortization of other intangible assets	2,007	2,863
FDIC insurance	6,558	4,135
OREO expense, net	(251)	(876)
Other	23,906	24,160
Total non-interest expense	286,889	234,641
Income before taxes	206,859	87,083
Income tax expense	53,711	24,271
Net income	153,148	62,812
Preferred stock dividends	6,991	2,050
Net income applicable to common shares	$ 146,157	$ 60,762
Net income per common share-Basic (usd per share)	$ 2.57	$ 1.05
Net income per common share-Diluted (usd per share)	2.54	1.04
Cash dividends declared per common share (usd per share)	$ 0.31	$ 0.28
Weighted average common shares outstanding (in shares)	56,904	57,620
Dilutive potential common shares (in shares)	681	575
Average common shares and dilutive common shares (in shares)	57,585	58,195
Wealth management
Non-interest income
Revenue from contracts with customers	$ 29,309	$ 25,941
Service charges on deposit accounts
Non-interest income
Revenue from contracts with customers	$ 12,036	$ 11,265