EMPLOYEE BENEFITS - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 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	$ 973	$ 856
Employee stock ownership plan, shares held under plan (in shares)	1,262,078		1,333,496
Employee stock ownership plan, unallocated shares (in shares)	0		0
Cash surrender value of life insurance	$ 34,280		$ 26,301
Bonus expense	2,304	2,170	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	34,280		26,301
Plan cost	504	$ 419	502
Plan obligation	$ 4,023		$ 3,667