CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Interest income:
Loans, including fees	$ 233,857	$ 224,482	$ 694,017	$ 687,183
Securities:
Taxable	8,986	8,276	25,073	28,133
Tax-exempt	15,873	15,001	47,917	43,421
Federal funds sold and other	2,152	1,429	5,014	5,258
Total interest income	260,868	249,188	772,021	763,995
Interest expense:
Deposits	12,139	28,401	43,468	112,826
Securities sold under agreements to repurchase	57	77	185	286
Federal Home Loan Bank advances and other borrowings	11,129	14,116	34,730	50,080
Total interest expense	23,325	42,594	78,383	163,192
Net interest income	237,543	206,594	693,638	600,803
Provision for credit losses	3,382	16,758	13,451	194,635
Net interest income after provision for credit losses	234,161	189,836	680,187	406,168
Noninterest income:
Total noninterest income	104,095	91,065	295,011	234,396
Noninterest expense:
Salaries and employee benefits	112,406	90,103	325,958	244,470
Equipment and occupancy	23,712	21,622	70,253	64,626
Other real estate (income) expense, net	(79)	1,795	(749)	7,098
Marketing and other business development	3,325	2,321	8,326	7,714
Postage and supplies	2,083	1,761	6,004	5,821
Amortization of intangibles	2,088	2,417	6,461	7,416
Other noninterest expense	25,316	23,833	73,434	66,005
Total noninterest expense	168,851	143,852	489,687	403,150
Income before income taxes	169,405	137,049	485,511	237,414
Income tax expense	32,828	26,404	91,716	35,969
Net income	136,577	110,645	393,795	201,445
Preferred stock dividends	(3,798)	(3,798)	(11,394)	(3,798)
Net income available to common shareholders	$ 132,779	$ 106,847	$ 382,401	$ 197,647
Per share information:
Basic net income per common share	$ 1.76	$ 1.42	$ 5.07	$ 2.62
Diluted net income per common share	$ 1.75	$ 1.42	$ 5.05	$ 2.62
Weighted average common shares outstanding:
Basic	75,494,286	75,240,664	75,449,900	75,417,663
Diluted	75,836,142	75,360,033	75,760,618	75,544,677
Service charges on deposit accounts
Noninterest income:
Total noninterest income	$ 11,435	$ 9,854	$ 28,648	$ 25,796
Investment services
Noninterest income:
Total noninterest income	9,648	6,734	26,836	21,944
Insurance sales commissions
Noninterest income:
Total noninterest income	2,557	2,284	8,188	7,755
Gain on mortgage loans sold, net
Noninterest income:
Total noninterest income	7,814	19,453	28,180	47,655
Investment gains on sales, net
Noninterest income:
Total noninterest income	0	651	366	986
Trust fees
Noninterest income:
Total noninterest income	5,049	3,986	14,798	12,114
Income from equity method investment
Noninterest income:
Total noninterest income	30,409	26,445	91,430	59,245
Other noninterest income
Noninterest income:
Total noninterest income	$ 37,183	$ 21,658	$ 96,565	$ 58,901