PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Additional Information (Detail) (USD $)	12 Months Ended						3 Months Ended	12 Months Ended			12 Months Ended			3 Months Ended				12 Months Ended																			12 Months Ended				3 Months Ended	12 Months Ended		3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Qualified and Registered Pension Plans	Dec. 31, 2011 Qualified and Registered Pension Plans	Dec. 31, 2010 Qualified and Registered Pension Plans	Jun. 30, 2012 Pension	Dec. 31, 2012 Pension	Dec. 31, 2011 Pension	Dec. 31, 2010 Pension	Dec. 31, 2012 United States Pension Plans	Dec. 31, 2011 United States Pension Plans	Dec. 31, 2010 United States Pension Plans	Dec. 31, 2011 Canadian Pension Plans	Dec. 31, 2012 Canadian Pension Plans	Dec. 31, 2012 United States Other Postretirement Benefit Plans	Dec. 31, 2011 United States Other Postretirement Benefit Plans	Dec. 31, 2012 Registered and Non registered Canadian Pension Plans	Dec. 31, 2010 Registered and Non registered Canadian Pension Plans	Dec. 31, 2012 Other Postretirement Benefits	Dec. 31, 2011 Other Postretirement Benefits	Dec. 31, 2010 Other Postretirement Benefits	Dec. 31, 2012 Non-Qualified U.S. Pension Plans	Dec. 31, 2012 Non Registered Canadian Pension Plans	Dec. 31, 2011 Non Registered Canadian Pension Plans	Dec. 31, 2010 Non Registered Canadian Pension Plans	Dec. 31, 2012 Canada	Dec. 31, 2011 Canada	Dec. 31, 2012 United States	Dec. 31, 2011 United States	Dec. 31, 2012 Fair Value, Inputs, Level 3	Dec. 31, 2011 Fair Value, Inputs, Level 3	Dec. 31, 2010 Fair Value, Inputs, Level 3	Dec. 31, 2012 Fair Value, Inputs, Level 3 Pension	Dec. 31, 2012 Fair Value, Inputs, Level 3 Non Registered Canadian Pension Plans	Dec. 31, 2011 Fair Value, Inputs, Level 3 Non Registered Canadian Pension Plans	Dec. 31, 2012 Investments Qualified and Registered Pension Plans	Dec. 31, 2012 Derivatives Qualified and Registered Pension Plans	Dec. 31, 2012 Investments we are allowed to invest Non Registered Canadian Pension Plans	Dec. 31, 2012 Collective Bargaining Arrangement Other Postretirement Benefits	Dec. 31, 2011 Plan Amendment [Member]	Dec. 31, 2012 Plan Amendment [Member]	Dec. 31, 2010 Plan Amendment [Member]	Dec. 31, 2011 Plan Amendment [Member] United States Other Postretirement Benefit Plans	Sep. 30, 2010 Plan Amendment [Member] United States Other Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Increase (reduction) in pension plan obligations	$ 655,000,000																																								$ (16,000,000)	$ 12,000,000	$ 0
Reduction in postretirement liability due to plan amendment	(103,000,000)	0	0																																									(108,000,000)
Prior service credit																																													(3,000,000)
Recognized curtailment charge												(9,000,000)	(5,000,000)						0		0	0
Settlement charges														(3,000,000)
Special termination charges												(6,000,000)	(5,000,000)
Discount rates											3.70%	4.50%		4.90%	4.10%	3.00%	4.10%
Increase in fair value of pension assets							16,000,000	16,000,000	138,000,000											0	0
Employer contributions and benefit payments								110,000,000	103,000,000									89,000,000		35,000,000	40,000,000		21,000,000
Pension plans with accumulated benefit obligations greater than plan assets, projected benefit obligations	6,600,000,000	5,800,000,000
Pension plans with accumulated benefit obligations greater than plan assets, accumulated benefit obligations	6,400,000,000	5,700,000,000
Pension plans with accumulated benefit obligations greater than plan assets, fair value of assets	5,000,000,000	4,700,000,000
Accumulated benefit obligation for all defined benefit pension plans	6,400,000,000	5,700,000,000
Fair value of plan assets				5,008,000,000	4,699,000,000			5,022,000,000	4,714,000,000	4,773,000,000										0	0	0		14,000,000	15,000,000						4,456,000,000	4,181,000,000	3,979,000,000	4,500,000,000	0	0
Fair value of plan assets, percent																																		89.00%
Percentage increase in fair value of pension assets							0.30%
Expected contribution to benefit plans during 2013																		88,000,000		37,000,000			19,000,000																	10,000,000
Expected return on plan assets				9.00%	9.50%	9.50%																		3.50%	4.75%	4.75%											7.30%	1.70%	7.00%
Annual rate of return on assets											14.80%
Actual return (loss) on plan assets	490,000,000	49,000,000	515,000,000	490,000,000				490,000,000	49,000,000											0	0
Weighted health care cost trend rate assumed for next year																											7.10%	7.30%	6.70%	6.80%
Number of employees covered under union-administered multiemployer pension plans	1,300
Multiemployer benefit plans contributions	4,000,000	4,000,000	4,000,000
Employer contributions to defined contribution plans	$ 19,000,000	$ 19,000,000	$ 12,000,000