PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Additional Information (Details) - USD ($)	3 Months Ended			12 Months Ended
	Dec. 31, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Feb. 19, 2016
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service cost (credit)(2)				$ 0	$ 0	$ 151,000,000
Change in liabilities due to change in actuarial assumptions				115,000,000
Pension plans with accumulated benefit obligations greater than plan assets, projected benefit obligations	$ 5,700,000,000			5,700,000,000	5,500,000,000
Pension plans with accumulated benefit obligations greater than plan assets, accumulated benefit obligations	5,600,000,000			5,600,000,000	5,400,000,000
Pension plans with accumulated benefit obligations greater than plan assets, fair value of assets	4,500,000,000			4,500,000,000	4,700,000,000
Accumulated benefit obligation for all defined benefit pension plans	6,400,000,000			6,400,000,000	6,100,000,000
Actual return on plan assets				$ 27,000,000	226,000,000	368,000,000
Number of employees covered under union-administered multiemployer pension plans				1,200
Multiemployer benefit plans contributions				$ 4,000,000	4,000,000	4,000,000
Employer contributions to defined contribution plans				$ 27,000,000	$ 21,000,000	20,000,000
Canada
Defined Benefit Plan Disclosure [Line Items]
Weighted health care cost trend rate assumed for next year				4.90%	5.00%
Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	455,000,000			$ 455,000,000	$ 546,000,000	$ 495,000,000
Qualified and Registered Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,341,000,000			$ 5,341,000,000	$ 5,481,000,000
Expected return on plan assets				9.00%	9.00%	9.00%
Expected return on plan assets, next fiscal year				8.00%
Registered Canadian Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Employer contributions and benefit payments				$ 16,000,000
Expected contribution to benefit plans during 2017				19,000,000
Pension
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,351,000,000			5,351,000,000	$ 5,491,000,000	$ 5,643,000,000
Projected benefit obligations	$ 6,469,000,000			6,469,000,000	6,211,000,000	6,698,000,000
Change in control enhanced benefits				5,000,000	0
Amortization of prior service cost (credit)(2)				(4,000,000)	(4,000,000)	(5,000,000)
Increase in fair value of pension assets		$ 7,000,000		7,000,000	57,000,000
Change in liabilities due to change in actuarial assumptions				(120,000,000)	309,000,000
Employer contributions and benefit payments				78,000,000	60,000,000
Percentage increase in fair value of pension assets		1.00%
Actual return on plan assets				$ 27,000,000	226,000,000
Pension | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, percent	8.50%			8.50%
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0			$ 0	0	0
Projected benefit obligations	$ 225,000,000			225,000,000	240,000,000	303,000,000
Change in control enhanced benefits				0	0
Amortization of prior service cost (credit)(2)				7,000,000	9,000,000	$ 161,000,000
Increase in fair value of pension assets				0	0
Change in liabilities due to change in actuarial assumptions				5,000,000	34,000,000
Employer contributions and benefit payments				21,000,000	23,000,000
Actual return on plan assets				0	$ 0
Expected contribution to benefit plans during 2017				21,000,000
Other Postretirement Benefits | Collective Bargaining Arrangement
Defined Benefit Plan Disclosure [Line Items]
Expected contribution to benefit plans during 2017				$ 7,000,000
United States Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rates, benefit obligation	4.30%			4.30%	4.50%
Annual rate of return on assets over 32 years				13.80%
Annual rate of return on assets over the past 5 years				8.10%
United States Other Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rates, benefit obligation	3.70%			3.70%	4.00%
Canadian Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rates, benefit obligation	3.70%			3.70%	4.00%
Canadian Other Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rates, benefit obligation	3.60%			3.60%	3.90%
Non-Qualified U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Employer contributions and benefit payments				$ 60,000,000
Expected contribution to benefit plans during 2017				$ 26,000,000
Qualified U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, required contribution				0
Employer contributions and benefit payments				$ 0
Expected contribution to benefit plans during 2017				0
Non Registered Canadian Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 10,000,000			10,000,000	$ 10,000,000
Employer contributions and benefit payments				$ 2,000,000
Expected return on plan assets				3.50%	3.50%	3.50%
Expected contribution to benefit plans during 2017				$ 3,000,000
Non Registered Canadian Pension Plans | Investments we are allowed to invest and manage
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets				7.00%
Non Registered Canadian Pension Plans | Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0			$ 0	$ 0
Pre Medicare | U.S.
Defined Benefit Plan Disclosure [Line Items]
Weighted health care cost trend rate assumed for next year				8.90%	7.20%
Health Reimbursement Account | U.S.
Defined Benefit Plan Disclosure [Line Items]
Weighted health care cost trend rate assumed for next year				4.50%	4.50%
Gain on postretirement plan amendment | Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service cost (credit)(2)						$ 151,000,000
Plum Creek | Qualified and Registered Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets				7.00%
Plum Creek | Pension
Defined Benefit Plan Disclosure [Line Items]
Change in control enhanced benefits				$ 5,000,000	$ 0	0
Plum Creek | Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Change in control enhanced benefits				0	$ 0	$ 0
Plum Creek | Non-Qualified U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligations							$ 50,000,000
Other Marketable Securities, Noncurrent	5,000,000			5,000,000			47,000,000
Supplemental Pension Benefit Payments				38,000,000
Change in control enhanced benefits			$ 5,000,000	$ 4,000,000
Plan assets sold during period	$ 4,000,000
Plum Creek | Qualified U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets							137,000,000
Projected benefit obligations							$ 149,000,000