CONDENSED FINANCIAL INFORMATION (parent company only) - Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Assets
Cash and due from banks	$ 112,649	$ 122,594
Premises and equipment	133,896	117,118
Interest receivable	97,664	85,070
Goodwill	712,002	712,002	$ 545,385
Cash surrender value of life insurance	306,301	308,311
Other assets	322,322	285,524
TOTAL ASSETS	18,405,887	18,002,199
Liabilities [Abstract]
Subordinated debentures and other borrowings	1,028,776	1,313,945
Interest payable	18,912	7,530
Other liabilities	289,033	263,209
Total Liabilities	16,158,174	15,967,429
Stockholders' equity	2,247,713	2,034,770	$ 1,912,571	$ 1,875,645
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	18,405,887	18,002,199
Parent
Assets
Cash and due from banks	100,858	56,739
Investment in subsidiaries	2,291,788	2,124,104
Premises and equipment	85	119
Interest receivable	7	6
Goodwill	448	448
Cash surrender value of life insurance	756	736
Other assets	8,954	6,851
TOTAL ASSETS	2,402,896	2,189,003
Liabilities [Abstract]
Subordinated debentures and other borrowings	150,174	150,115
Interest payable	1,383	979
Other liabilities	3,626	3,139
Total Liabilities	155,183	154,233
Stockholders' equity	2,247,713	2,034,770
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 2,402,896	$ 2,189,003