EMPLOYEE BENEFITS - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Employee stock ownership plan, maximum employer contribution as a percentage of participant's qualified compensation	5.00%
Employee stock ownership plan, total contributions accrued or paid	$ 383	$ 343
Employee stock ownership plan, shares held under plan (in shares)	1,227,096		1,224,697
Employee stock ownership plan, unallocated shares (in shares)	0		0
Cash surrender value of life insurance	$ 34,713		$ 34,495
Bonus expense	478	715	3,265
Executive Incentive Retirement Plan | Postretirement Life Insurance | Nonqualified Plan | Unfunded Plan
Defined Benefit Plan Disclosure [Line Items]
Cash surrender value of life insurance	34,713		34,495
Plan cost	296	$ 285	602
Plan obligation	$ 4,337		$ 4,081