RETIREMENT BENEFITS - Contributions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
U.S. | Pension Plans
Defined Benefit Plan, Expected Future Employer Contributions [Abstract]
Estimated future cash contributions	$ 0
Cash contributions paid by the Company	425	$ 0
Estimated benefits paid directly by Company	58
Benefits paid directly by the Company	56	55
U.S. | Postretirement Benefit Plans
Defined Benefit Plan, Expected Future Employer Contributions [Abstract]
Estimated future cash contributions	0
Cash contributions paid by the Company	0	145
Estimated benefits paid directly by Company	6
Benefits paid directly by the Company	4	5
Non-U.S. | Pension Plans
Defined Benefit Plan, Expected Future Employer Contributions [Abstract]
Estimated future cash contributions	111
Cash contributions paid by the Company	111	140
Estimated benefits paid directly by Company	53
Benefits paid directly by the Company	39	42
Non-U.S. | Postretirement Benefit Plans
Defined Benefit Plan, Expected Future Employer Contributions [Abstract]
Estimated future cash contributions	4
Cash contributions paid by the Company	221	3
Estimated benefits paid directly by Company	6
Benefits paid directly by the Company	$ 4	$ 6