EMPLOYEE BENEFIT PLANS - PERIODIC BENEFIT COSTS AND ASSUMPTIONS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Pension Benefits
Net Periodic Benefit Costs:
Service cost	$ 32	$ 35	$ 30
Interest cost	35	33	36
Expected return on plan assets	(44)	(42)	(39)
Amortization of prior service cost		1	1
Amortization of net loss	10	12	4
Curtailment loss		1
Settlement loss recognized		1
Special termination benefit	1
Net periodic benefit costs	$ 34	$ 41	$ 32
Weighted-Average Assumptions to Determine Benefit Obligations
Discount rate (as a percent)	3.90%	4.20%
Increase in future compensation levels (as a percent)	3.20%	3.30%
Weighted-Average Assumptions to Determine the Net Periodic Benefit Cost
Discount rate (as a percent)	4.20%	3.80%	4.90%
Expected long-term rate of return on assets (as a percent)	6.40%	6.70%	6.70%
Increase in future compensation levels (as a percent)	3.30%	3.50%	3.50%
Postretirement Benefits
Net Periodic Benefit Costs:
Interest cost	$ 7	$ 5	$ 6
Amortization of net loss			(1)
Curtailment loss			(2)
Net periodic benefit costs	$ 7	$ 5	$ 3
Weighted-Average Assumptions to Determine Benefit Obligations
Discount rate (as a percent)	10.80%	11.40%
Weighted-Average Assumptions to Determine the Net Periodic Benefit Cost
Discount rate (as a percent)	11.40%	9.80%	10.00%