OTHER COMPREHENSIVE INCOME (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Pension and postretirement benefits [Abstract]
Amortization of net actuarial loss, Gross Amount	[1]	$ 1,209	$ 1,037
Amortization of net actuarial loss, Income Tax (Provision) Benefit	[1]	(463)	(388)
Amortization of net actuarial loss, Net Amount	[1]	746	649
Actuarial gains, Gross Amount	[1]	0	0
Actuarial gains, Income Tax (Provision) Benefit	[1]	0	0
Actuarial gains, Net Amount	[1]	0	0
Total other comprehensive income (loss), Gross Amount		1,209	1,037
Total other comprehensive income (loss), Income Tax (Provision) Benefit		(463)	(388)
Total other comprehensive income, net of taxes		$ 746	$ 649

[1] Actuarial losses are amortized into costs of sales and operating expenses or selling, general and administrative expenses as appropriate. (See Note 10 - Retirement Plans)