BENEFIT PLANS (Components of Net Periodic Benefit Cost- Other Postretirement Benefits) (Details) - Postretirement Benefits [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Components of Net Periodic Benefit Cost
Service cost	$ 330	$ 340	$ 659	$ 679
Interest cost	347	310	694	620
Amortization of prior service credit	(979)	(990)	(1,959)	(1,981)
Amortization of actuarial gain	(327)	(325)	(654)	(649)
Net periodic benefit cost (credit)	(629)	(665)	(1,260)	(1,331)
Pretax reclassifications from AOCI included in net periodic postretirement benefit credit	$ (1,306)	$ (1,315)	$ (2,613)	$ (2,630)