PENSIONS AND OTHER POST-RETIREMENT BENEFITS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Pension Benefits
Components of the net periodic benefit cost
Service cost	$ 2,002	$ 1,802	$ 6,006	$ 5,406
Interest cost	3,016	2,955	9,048	8,865
Expected return on plan assets	(3,478)	(3,131)	(10,434)	(9,393)
Amortization of prior service cost	4	4	12	12
Recognized actuarial loss	2,156	1,027	6,468	3,081
Net periodic benefit cost	3,700	2,657	11,100	7,971
Pension Benefits | Cost of sales
Components of the net periodic benefit cost
Net periodic benefit cost	2,200		6,700
Pension Benefits | Selling, general, and administrative expenses
Components of the net periodic benefit cost
Net periodic benefit cost	1,500		4,400
Other Benefits
Components of the net periodic benefit cost
Service cost	9	12	27	36
Interest cost	81	114	243	342
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	(844)	(844)	(2,532)	(2,532)
Recognized actuarial loss	192	246	576	738
Net periodic benefit cost	$ (562)	$ (472)	$ (1,686)	$ (1,416)