BUSINESS COMBINATIONS - Corporate Development and Restructuring Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Salaries, benefits and other compensation	$ 283,905	$ 214,167	$ 194,317
Occupancy expense	40,885	32,802	32,105
Equipment expense	40,994	29,040	23,793
Professional fees	18,497	15,614	18,757
Data processing and operations expenses	20,876	14,074	12,600
Marketing expense	7,230	5,413	5,677
Total non interest expenses	574,326	$ 378,516	$ 368,844
BMBC
Business Acquisition [Line Items]
Salaries, benefits and other compensation	12,541
Occupancy expense	9,356
Equipment expense	20,950
Professional fees	13,025
Data processing and operations expenses	121
Marketing expense	3,133
Other operating expense, net	6,097
Total non interest expenses	$ 65,223