PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS Components of Net Periodic Benefit Costs (Credits) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Defined Benefit Plan Disclosure [Line Items]
Document Period End Date			Sep. 30, 2017
Pension
Defined Benefit Plan Disclosure [Line Items]
Service cost(1)	$ 9	$ 13	$ 26	$ 37
Interest cost	66	70	198	207
Expected return on plan assets	(101)	(125)	(306)	(371)
Amortization of actuarial loss	48	39	145	117
Amortization of prior service cost	1	1	3	3
Accelerated pension costs included in Plum Creek merger-related costs (Note 15)	0	0	0	5
Total net periodic benefit cost (credit)	23	(2)	66	(2)
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Interest cost	2	2	6	7
Amortization of actuarial loss	2	2	6	6
Amortization of prior service cost	(2)	(2)	(6)	(6)
Total net periodic benefit cost (credit)	$ 2	2	$ 6	7
Discontinued Operations [Member] | Pension
Defined Benefit Plan Disclosure [Line Items]
Service cost(1)		$ 3		$ 10