INCOME TAXES - Uncertain Tax Positions and Interest and Penalties - Additional Disclosures (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes
Unrecognized tax benefits that would impact effective tax rate if recognized	$ 46	$ 43
Liability for uncertain tax positions	67	62	$ 55
Reasonably possible reduction in the liability for uncertain tax positions	9
Other Noncurrent Liabilities
Income Taxes
Liability for uncertain tax positions	64	59
Other Noncurrent Assets
Income Taxes
Liability for uncertain tax positions	$ 3	$ 3