PENSIONS AND OTHER POST-RETIREMENT BENEFITS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Pension Benefits
Components of the net periodic benefit cost
Service cost	$ 1,734	$ 2,002	$ 3,468	$ 4,004
Interest cost	3,335	3,016	6,670	6,032
Expected return on plan assets	(3,936)	(3,478)	(7,872)	(6,956)
Amortization of prior service cost	3	4	6	8
Recognized actuarial loss	502	2,156	1,004	4,312
Net periodic benefit cost	1,638	3,700	3,276	7,400
Pension Benefits | Cost of sales [Member]
Components of the net periodic benefit cost
Net periodic benefit cost	900	2,200	1,900	4,400
Pension Benefits | Selling, general, and administrative expenses [Member]
Components of the net periodic benefit cost
Net periodic benefit cost	700	1,500	1,400	3,000
Other Benefits
Components of the net periodic benefit cost
Service cost	6	9	12	18
Interest cost	91	81	182	162
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	(561)	(844)	(1,122)	(1,688)
Recognized actuarial loss	154	192	308	384
Net periodic benefit cost	$ (310)	$ (562)	$ (620)	$ (1,124)