POSTRETIREMENT BENEFIT PLANS - Additional information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($)
Postretirement benefit plans
Pension settlement expense	$ 89
Pension settlement expense, net of tax	66
Supplemental Benefit Plan
Postretirement benefit plans
Benefit	700
Pension settlement expense	89
Pension settlement expense, net of tax	$ 100