CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Interest and dividend income:
Loans	$ 890,562	$ 747,901	$ 719,153
Investment securities	102,505	102,922	72,893
Money market investments and interest-bearing cash accounts	30,419	11,791	2,662
Total interest and dividend income	1,023,486	862,614	794,708
Interest expense:
Deposits	185,461	46,361	41,482
Advances from the FHLB:
Short-term	4,811	1,475	0
Long-term	19,797	3,661	8,199
Other short-term borrowings	3	16	0
Other long-term borrowings	13,535	8,253	5,135
Total interest expense	226,376	67,321	64,779
Net interest income	797,110	795,293	729,929
Provision for credit losses - expense (benefit):
Financing Receivable Excluding Accrued Interest Credit Loss Expense (Reversal)	66,644	25,679	(61,720)
Unfunded loan commitments	365	2,736	(3,568)
Debt securities	(6,069)	(719)	(410)
Provision for credit losses - expense (benefit)	60,940	27,696	(65,698)
Net interest income after provision for credit losses	736,170	767,597	795,627
Non-interest income:
Service charges and fees on deposit accounts	38,042	37,823	35,284
Mortgage banking activities	10,587	15,260	24,998
Gain on early extinguishment of debt	1,605	0	0
Insurance commission income	12,763	13,743	11,945
Card and processing income	43,909	40,416	36,508
Other non-interest income	25,788	15,850	12,429
Total non-interest income	132,694	123,092	121,164
Non-interest expenses:
Employees' compensation and benefits	222,855	206,038	200,457
Occupancy and equipment	85,911	88,277	93,253
Business promotion	19,626	18,231	15,359
Professional service fees	45,841	47,848	59,956
Taxes, other than income taxes	21,236	20,267	22,151
Federal Deposit Insurance Corporation (FDIC) deposit insurance	14,873	6,149	6,544
Net gain on OREO operations	(7,138)	(5,826)	(2,160)
Credit and debit card processing expenses	25,997	22,736	22,169
Communications	8,561	8,723	9,387
Merger and restructuring costs	0	0	26,435
Other non-interest expenses	33,666	30,662	35,423
Total non-interest expenses	471,428	443,105	488,974
Income before income taxes	397,436	447,584	427,817
Income tax expense	94,572	142,512	146,792
Net income	302,864	305,072	281,025
Net income attributable to common stockholders	$ 302,864	$ 305,072	$ 277,338
Net income per common share:
Basic	$ 1.72	$ 1.60	$ 1.32
Diluted	$ 1.71	$ 1.59	$ 1.31
Short-term Debt [Member]
Interest expense:
Securities sold under agreements to repurchase	$ 2,769	$ 1,017	$ 0
Long-term Debt [Member]
Interest expense:
Securities sold under agreements to repurchase	$ 0	$ 6,538	$ 9,963