PENSIONS AND OTHER POSTRETIREMENT BENEFITS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Pension Benefits
Components of the net periodic benefit cost
Service cost	$ 1,802	$ 2,628	$ 5,406	$ 7,884
Interest cost	2,955	2,799	8,865	8,397
Expected return on plan assets	(3,131)	(3,249)	(9,393)	(9,747)
Amortization of prior service cost	4	9	12	27
Recognized actuarial loss	1,027	283	3,081	849
Net periodic benefit cost (gain)	2,657	2,470	7,971	7,410
Other Benefits
Components of the net periodic benefit cost
Service cost	12	119	36	357
Interest cost	114	320	342	960
Amortization of prior service cost	(844)	(303)	(2,532)	(909)
Recognized actuarial loss	246	166	738	498
Net periodic benefit cost (gain)	$ (472)	$ 302	$ (1,416)	$ 906