BENEFIT PLANS (Components of Net Periodic Benefit Cost- Other Postretirement Benefits) (Details) - Postretirement Benefits [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Components of Net Periodic Benefit Cost
Service cost	$ 329	$ 339
Interest cost	347	310
Amortization of prior service credit	(980)	(991)
Amortization of actuarial gain	(327)	(324)
Net periodic benefit cost (credit)	(631)	(666)
Pretax reclassifications from AOCI included in net periodic postretirement benefit credit	$ (1,307)	$ (1,315)