OTHER COMPREHENSIVE INCOME (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Pension and postretirement benefits [Abstract]
Amortization of net actuarial loss, Gross Amount	[1]	$ 550	$ 568
Amortization of net actuarial loss, Income Tax Provision	[1]	(139)	(138)
Amortization of net actuarial loss, Net Amount	[1]	411	430
Foreign currency translation, Gross Amount		129	420
Foreign currency translation, Income Tax Provision		0	0
Foreign currency translation, Net Amount		129	420
Total other comprehensive income, Gross Amount		679	988
Total other comprehensive income, Income Tax Provision		(139)	(8,063)
Total other comprehensive income (loss), net of taxes		540	(7,075)
ASU 2018-02 [Member]
Pension and postretirement benefits [Abstract]
Reclassification to retained earnings of stranded tax effects from tax reform, Gross Amount		0	0
Reclassification to retained earnings of stranded tax effects from tax reform, Income Tax Provision Benefit		0	(7,925)
Reclassification to retained earnings of stranded tax effects from tax reform, Net Amount		$ 0	$ (7,925)

[1] (Actuarial gains/(losses) are amortized into other income (expense). (See Note 14 - Retirement Plans)