Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Interest income:
Loans	$ 687,852	$ 456,007	$ 348,615
Debt securities:
Taxable	39,510	28,267	18,030
Nontaxable	22,717	18,838	13,814
Interest-earning deposits	13,430	10,599	1,496
Dividends on equity securities	1,410	1,371	1,275
Total interest income	764,919	515,082	383,230
Interest expense:
Interest Expense, Deposits	183,723	30,158	10,668
Subordinated debentures and notes	9,781	9,166	10,960
FHLB advances	2,752	599	803
Other borrowings	6,071	1,256	605
Total interest expense	202,327	41,179	23,036
Net interest income	562,592	473,903	360,194
Provision (benefit) for credit losses	36,605	(611)	13,385
Net interest income after provision (benefit) for credit losses	525,987	474,514	346,809
Noninterest income:
Total noninterest income	68,725	59,162	67,743
Noninterest expense:
Employee compensation and benefits	164,566	147,029	124,904
Deposit costs	72,293	31,082	14,211
Occupancy	16,526	17,640	16,286
Data processing	15,196	13,513	12,242
Professional fees	5,719	7,079	4,289
Branch-closure expenses	0	0	3,441
Merger-related expenses	0	0	22,082
Other expense	73,886	57,873	48,464
Noninterest expense	348,186	274,216	245,919
Income before income tax expense	246,526	259,460	168,633
Income tax expense	52,467	56,417	35,578
Net income	194,059	203,043	133,055
Preferred stock dividends	3,750	4,041	0
Net income available to common shareholders	$ 190,309	$ 199,002	$ 133,055
Earnings per common share:
Basic (usd per share)	$ 5.09	$ 5.32	$ 3.86
Diluted (usd per share)	$ 5.07	$ 5.31	$ 3.86
Deposit Account [Member]
Noninterest income:
Total noninterest income	$ 16,559	$ 18,326	$ 15,428
Fiduciary and Trust [Member]
Noninterest income:
Total noninterest income	10,030	10,010	10,259
Card Services Revenue [Member]
Noninterest income:
Total noninterest income	10,028	11,551	11,880
Tax credit activity, net [Member]
Noninterest income:
Total noninterest income	9,196	2,558	8,028
Total other noninterest income
Noninterest income:
Total noninterest income	$ 22,912	$ 16,717	$ 22,148