BUSINESS COMBINATIONS - Narrative (Details) - USD ($) $ in Thousands					9 Months Ended		12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jan. 01, 2023	Aug. 01, 2022	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
BUSINESS COMBINATIONS
Goodwill	$ 272,520				$ 272,520		$ 272,520
Provision for credit loss					$ 2,650	$ 13,250
Heritage Southeast Bank
BUSINESS COMBINATIONS
Entity shares issued per acquiree share (in shares)			0.965
Purchase price	221,538		$ 221,538
Business acquisition, equity interest issued or issuable, number of shares (in shares)			6,920,422
Cash received in lieu of fractional shares			$ 16
Goodwill	91,925		91,445				91,925
Provision for credit loss			3,200				10,700
Core deposit intangible	$ 43,739		43,739				$ 43,739
Heritage Southeast Bank | Core Deposits
BUSINESS COMBINATIONS
Core deposit intangible			$ 43,700
Acquired finite-lived intangible assets, weighted average useful life			10 years
Beach Bancorp
BUSINESS COMBINATIONS
Entity shares issued per acquiree share (in shares)				0.1711
Purchase price		$ 101,470		$ 101,470
Business acquisition, equity interest issued or issuable, number of shares (in shares)				3,498,936
Cash received in lieu of fractional shares				$ 1
Goodwill		23,653		21,822		23,653
Provision for credit loss				1,300
Core deposit intangible		$ 9,791		$ 9,791		$ 9,791
Assumed options, additional shares				310,427
Beach Bancorp | Core Deposits
BUSINESS COMBINATIONS
Acquired finite-lived intangible assets, weighted average useful life				10 years