OTHER COMPREHENSIVE INCOME (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Pension and postretirement benefits [Abstract]
Amortization of net actuarial loss, Gross Amount	[1]	$ 568	$ 1,209
Amortization of net actuarial loss, Income Tax (Provision) Benefit	[1]	(138)	(463)
Amortization of net actuarial loss, Net Amount	[1]	430	746
Foreign currency translation, Gross Amount		420	0
Foreign currency translation, Income Tax (Provision) Benefit		0	0
Foreign currency translation, Net Amount		420	0
Total other comprehensive income (loss), Gross Amount		988	1,209
Total other comprehensive income (loss), Income Tax (Provision) Benefit		(8,063)	(463)
Total other comprehensive income (loss), net of taxes		(7,075)	746
ASU 2018-02 [Member]
Pension and postretirement benefits [Abstract]
Adoption of ASU 2018-02 - reclassification to retained earnings, Gross Amount		0	0
Adoption of ASU 2018-02 - reclassification to retained earnings, Income Tax (Provision) Benefit		(7,925)	0
Adoption of ASU 2018-02 - reclassification to retained earnings, Net Amount		$ (7,925)	$ 0

[1] Actuarial losses are amortized into other income (expense). (See Note 13 - Retirement Plans)