OTHER COMPREHENSIVE INCOME (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Pension and postretirement benefits [Abstract]
Amortization of net actuarial loss, Gross Amount	[1]	$ 822	$ 1,193	$ 2,939	$ 3,575
Amortization of net actuarial loss, Income Tax (Provision) Benefit	[1]	(315)	(455)	(1,125)	(1,367)
Amortization of net actuarial loss, Net Amount	[1]	507	738	1,814	2,208
Actuarial gains (losses), Gross Amount	[1]	0	(2)	22,014	(6,437)
Actuarial gains (losses), Income Tax (Provision) Benefit	[1]	0	(1)	(8,435)	2,464
Actuarial gains (losses), Net Amount	[1]	0	(3)	13,579	(3,973)
Foreign currency translation, Gross Amount	[1]	(164)	0	(164)	0
Foreign currency translation, Income Tax (Provision) Benefit	[1]	0	0	0	0
Foreign currency translation, Net Amount	[1]	(164)	0	(164)	0
Total other comprehensive income (loss), Gross Amount		658	1,191	24,789	(2,862)
Total other comprehensive income (loss), Income Tax (Provision) Benefit		(315)	(456)	(9,560)	1,097
Total other comprehensive income (loss), net of taxes		$ 343	$ 735	$ 15,229	$ (1,765)

[1] Actuarial gains/(losses) are amortized into costs of sales and operating expenses or selling, general and administrative expenses as appropriate. (See Note 11 - Retirement Plans)