PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Assumptions We Use in Estimating Health Care Benefit Costs (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
United States
Defined Benefit Plan Disclosure [Line Items]
Weighted health care cost trend rate assumed for next year	6.70%	6.80%
Rate to which cost trend rate is assumed to decline (ultimate trend rate)	4.50%	4.50%
Year that the rate reaches the ultimate trend rate	2029	2029
Canada
Defined Benefit Plan Disclosure [Line Items]
Weighted health care cost trend rate assumed for next year	7.10%	7.30%
Rate to which cost trend rate is assumed to decline (ultimate trend rate)	4.50%	4.50%
Year that the rate reaches the ultimate trend rate	2030	2030