Consolidated Statements of Income (unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Interest income:
Loans, including fees	$ 478,360	$ 419,355	$ 942,048	$ 812,720
Investment securities:
Taxable	38,747	41,254	78,492	82,819
Tax-exempt	5,769	5,586	11,337	12,144
Federal funds sold, securities purchased under agreements to resell and interest-bearing deposits with banks	8,248	11,858	16,502	20,779
Total interest income	531,124	478,053	1,048,379	928,462
Interest expense:
Deposits	165,481	100,787	325,643	156,729
Federal funds purchased and securities sold under agreements to repurchase	4,983	3,535	9,710	6,388
Corporate and subordinated debentures	5,999	5,823	12,008	11,558
Other borrowings	4,402	6,165	6,823	10,781
Total interest expense	180,865	116,310	354,184	185,456
Net interest income	350,259	361,743	694,195	743,006
Provision for credit losses	3,889	38,389	16,575	71,480
Net interest income after provision for credit losses	346,370	323,354	677,620	671,526
Noninterest income:
Securities gains, net				45
Other income	15,565	7,864	28,744	17,730
Total noninterest income	75,225	77,214	146,783	148,569
Noninterest expense:
Salaries and employee benefits	151,435	147,342	301,888	291,402
Occupancy expense	22,453	22,196	45,030	43,729
Information services expense	23,144	21,119	45,497	41,044
OREO and loan related expense	1,307	(14)	1,913	155
Amortization of intangibles	5,744	7,028	11,742	14,327
Supplies, printing and postage expense	2,526	2,554	5,066	5,194
Professional fees	3,906	4,364	7,021	8,066
FDIC assessment and other regulatory charges	7,771	9,819	16,305	16,113
FDIC special assessment	619		4,473
Advertising and marketing	2,594	1,521	4,578	3,639
Merger, branch consolidation, severance related and other expense	5,785	1,808	10,298	11,220
Other expense	21,463	24,889	44,226	48,242
Total noninterest expense	248,747	242,626	498,037	483,131
Earnings:
Income before provision for income taxes	172,848	157,942	326,366	336,964
Provision for income taxes	40,478	34,495	78,940	73,591
Net income	$ 132,370	$ 123,447	$ 247,426	$ 263,373
Earnings per common share:
Basic (in dollars per share)	$ 1.74	$ 1.62	$ 3.24	$ 3.47
Diluted (in dollars per share)	$ 1.73	$ 1.62	$ 3.23	$ 3.45
Weighted average common shares outstanding:
Basic (in shares)	76,251	76,058	76,276	75,981
Diluted (in shares)	76,607	76,418	76,630	76,394
Fees on deposit accounts
Noninterest income:
Noninterest income	$ 33,842	$ 33,101	$ 66,987	$ 62,960
Mortgage banking income
Noninterest income:
Noninterest income	5,912	4,354	12,081	8,686
Trust and investment services income
Noninterest income:
Noninterest income	11,091	9,823	21,482	19,760
Correspondent banking and capital markets income
Noninterest income:
Noninterest income	4,860	19,187	9,171	32,781
SBA income
Noninterest income:
Noninterest income	$ 3,955	$ 2,885	$ 8,318	$ 6,607