Consolidated Statements of Income (unaudited) - USD ($) shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Interest income:
Loans, including fees	$ 443,805,000	$ 312,856,000	$ 1,256,525,000	$ 818,473,000
Investment securities:
Taxable	40,330,000	39,300,000	123,149,000	108,368,000
Tax-exempt	5,543,000	5,986,000	17,687,000	15,937,000
Federal funds sold, securities purchased under agreements to resell and interest-bearing deposits with banks	10,831,000	18,190,000	31,610,000	30,359,000
Total interest income	500,509,000	376,332,000	1,428,971,000	973,137,000
Interest expense:
Deposits	133,944,000	7,534,000	290,673,000	17,040,000
Federal funds purchased and securities sold under agreements to repurchase	4,291,000	1,506,000	10,679,000	2,556,000
Corporate and subordinated debentures	6,014,000	4,958,000	17,572,000	13,874,000
Other borrowings	889,000		11,670,000
Total interest expense	145,138,000	13,998,000	330,594,000	33,470,000
Net interest income	355,371,000	362,334,000	1,098,377,000	939,667,000
Provision for credit losses	32,709,000	23,876,000	104,189,000	34,713,000
Net interest income after provision for credit losses	322,662,000	338,458,000	994,188,000	904,954,000
Noninterest income:
Securities gains, net	0	30,000	45,000	30,000
Other income	12,035,000	8,004,000	29,765,000	22,770,000
Total noninterest income	72,848,000	73,053,000	221,417,000	245,855,000
Noninterest expense:
Salaries and employee benefits	146,146,000	139,554,000	437,548,000	414,264,000
Occupancy expense	22,251,000	22,490,000	65,980,000	67,089,000
Information services expense	21,428,000	20,714,000	62,472,000	59,854,000
OREO and loan related expense	613,000	532,000	768,000	291,000
Amortization of intangibles	6,616,000	7,837,000	20,943,000	25,178,000
Supplies, printing and postage expense	2,623,000	2,621,000	7,817,000	7,210,000
Professional fees	3,456,000	3,495,000	11,522,000	11,575,000
FDIC assessment and other regulatory charges	8,632,000	6,300,000	24,745,000	16,444,000
Advertising and marketing	3,009,000	2,170,000	6,648,000	6,219,000
Merger, branch consolidation and severance related expense	164,000	13,679,000	11,384,000	29,345,000
Other expense	23,268,000	21,041,000	71,510,000	62,733,000
Total noninterest expense	238,206,000	240,433,000	721,337,000	700,202,000
Earnings:
Income before provision for income taxes	157,304,000	171,078,000	494,268,000	450,607,000
Provision for income taxes	33,160,000	38,035,000	106,751,000	98,060,000
Net income	$ 124,144,000	$ 133,043,000	$ 387,517,000	$ 352,547,000
Earnings per common share:
Basic (in dollars per share)	$ 1.63	$ 1.76	$ 5.10	$ 4.75
Diluted (in dollars per share)	$ 1.62	$ 1.75	$ 5.07	$ 4.71
Weighted average common shares outstanding:
Basic (in shares)	76,139	75,606	76,034	74,185
Diluted (in shares)	76,571	76,182	76,446	74,791
Fees on deposit accounts
Noninterest income:
Noninterest income	$ 32,830,000	$ 30,326,000	$ 95,790,000	$ 91,198,000
Mortgage banking income
Noninterest income:
Noninterest income	2,478,000	2,262,000	11,164,000	18,336,000
Trust and investment services income
Noninterest income:
Noninterest income	9,556,000	9,603,000	29,316,000	29,152,000
Correspondent banking and capital markets income
Noninterest income:
Noninterest income	12,916,000	16,427,000	45,697,000	70,445,000
SBA income
Noninterest income:
Noninterest income	$ 3,033,000	$ 6,401,000	$ 9,640,000	$ 13,924,000