PENSIONS AND OTHER POST-RETIREMENT BENEFITS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Compensation and Retirement Disclosure [Abstract]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments			$ 7,100
Pension Benefits
Components of the net periodic benefit cost
Service cost	$ 1,851	$ 1,734	5,626	$ 5,202
Interest cost	3,055	3,335	9,283	10,005
Expected return on plan assets	(3,564)	(3,936)	(10,874)	(11,808)
Amortization of prior service cost	0	3	0	9
Recognized actuarial loss	1,158	502	5,490	1,506
Net periodic benefit cost	2,500	1,638	9,525	4,914
Pension Benefits | Cost of sales
Components of the net periodic benefit cost
Net periodic benefit cost	1,500	900	5,200	2,800
Pension Benefits | Selling, general, and administrative expenses
Components of the net periodic benefit cost
Net periodic benefit cost	1,000	700	4,300	2,100
Other Benefits
Components of the net periodic benefit cost
Service cost	(2)	6	5	18
Interest cost	60	91	221	273
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	(420)	(561)	(564)	(1,683)
Recognized actuarial loss	(209)	154	(25)	462
Net periodic benefit cost	$ (571)	$ (310)	$ (363)	$ (930)