LOANS AND ALLOWANCE FOR CREDIT LOSSES - Mortgage Banking (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total residential loans included in held for sale loans	$ 7,505		$ 7,505		$ 23,988
Residential mortgages | Total residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total residential loans included in held for sale loans	7,500		7,500		24,000
Forward delivery commitments	14,500		14,500		$ 50,600
Sale of loans	28,500	$ 86,200	153,900	$ 156,000
Net gains on sales of loans	$ 682	$ 2,200	$ 3,600	$ 3,100