BUSINESS COMBINATIONS (Additional Information) (Details) - USD ($) $ in Thousands		6 Months Ended
	Jan. 07, 2022	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Asset Acquisition [Line Items]
Other assets acquisition	$ 197,100
Total assets		$ 16,759,993		$ 15,883,697
Cash and cash equivalents		696,709		1,732,548
Premises and equipment		47,100		49,096
Bank owned life insurance (BOLI)		259,958		251,570
Other assets		111,999		118,301
Goodwill		765,822		663,707
Fair value of liabilities assumed		80,230	$ 110,430
Noninterest-bearing deposits		8,881,223		8,104,056
Interest-bearing deposits		5,190,996		$ 4,872,386
Suncrest Bank
Asset Acquisition [Line Items]
Cash consideration	39,600	39,600
Total assets	1,380,000
Cash and cash equivalents	329,000
Fair value of acquired investment securities	131,100	131,100
Acquired net loans at fair value	765,900	765,900
Premises and equipment	6,100
Bank owned life insurance (BOLI)	9,000	9,000
Other assets	33,700
Loans recorded at a fair value	224,700
Loans net of a discount	13,100
Loans credit discount	8,600
Deposit premium		3,900
Goodwill		102,100
Fair value of liabilities assumed	1,190,000
Noninterest-bearing deposits	512,800
Interest-bearing deposits	669,800
Other liabilities	6,200
Non-recurring merger related expenses		$ 6,000
Suncrest Bank | Core Deposits
Asset Acquisition [Line Items]
Deposit premium	3,900
Goodwill	$ 102,100