PENSIONS AND OTHER POSTRETIREMENT BENEFITS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Pension Benefits
Components of the net periodic benefit cost
Service cost	$ 2,002	$ 1,802	$ 4,004	$ 3,604
Interest cost	3,016	2,955	6,032	5,910
Expected return on plan assets	(3,478)	(3,131)	(6,956)	(6,262)
Amortization of prior service cost	4	4	8	8
Recognized actuarial loss	2,156	1,027	4,312	2,054
Net periodic benefit cost	3,700	2,657	7,400	5,314
Pension Benefits | Cost of sales
Components of the net periodic benefit cost
Net periodic benefit cost	2,200		4,400
Pension Benefits | Selling, general, and administrative expenses
Components of the net periodic benefit cost
Net periodic benefit cost	1,500		3,000
Other Benefits
Components of the net periodic benefit cost
Service cost	9	12	18	24
Interest cost	81	114	162	228
Amortization of prior service cost	(844)	(844)	(1,688)	(1,688)
Recognized actuarial loss	192	246	384	492
Net periodic benefit cost	$ (562)	$ (472)	$ (1,124)	$ (944)