EMPLOYEE BENEFITS - Narrative (Details) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
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	$ 634	$ 551
Employee stock ownership plan, shares held under plan (in shares)	1,298,716		1,333,504
Employee stock ownership plan, unallocated shares (in shares)	0		0
Cash surrender value of life insurance	$ 34,039		$ 26,301
Bonus expense	1,550	1,513	2,943
Executive Incentive Retirement Plan | Postretirement Life Insurance | Nonqualified Plan | Unfunded Plan
Defined Benefit Plan Disclosure [Line Items]
Cash surrender value of life insurance	34,039		26,301
Plan cost	409	$ 344	502
Plan obligation	$ 3,967		$ 3,667