GOODWILL AND CORE DEPOSIT INTANGIBLE ASSETS - Changes in Carrying Amount of Goodwill and Intangibles (Details) - USD ($) $ in Thousands		12 Months Ended
	Oct. 01, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Goodwill [Roll Forward]
Balance, beginning		$ 223,642	$ 223,642	$ 223,642
Acquired intangibles		273,618
Balance, ending		497,260	223,642	223,642
Finite-Lived Intangible Assets [Roll Forward]
Balance, beginning		14,658
Amortization		(9,303)	(3,296)	(3,922)
Balance, ending		143,525	14,658
Core Deposit Intangibles
Finite-Lived Intangible Assets [Roll Forward]
Balance, beginning		14,658	17,954	21,876
Acquired intangibles		138,150
Amortization		(9,283)	(3,296)	(3,922)
Balance, ending		143,525	14,658	17,954
Servicing Assets
Finite-Lived Intangible Assets [Roll Forward]
Balance, beginning		0	0	0
Acquired intangibles		329
Amortization		(20)	0	0
Balance, ending		$ 309	$ 0	$ 0
CBTX
Goodwill [Roll Forward]
Balance, ending	$ 273,618
CBTX | Core Deposit Intangibles
Finite-Lived Intangible Assets [Roll Forward]
Acquired intangibles	$ 138,200