FAIR VALUE - Put and Call Options Measured at Fair Value (Details) $ in Millions	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Put option | Other long-term liabilities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of financial liability	$ 28	$ 224
Call option | Other long-term assets
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of financial asset	$ 557	$ 246
Options | Level 3 fair value measurement | Annualized volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Significant unobservable inputs	0.198
Options | Level 3 fair value measurement | Secured credit rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Significant unobservable inputs	0.022
Options | Level 3 fair value measurement | Long-term net operating profit after tax
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Significant unobservable inputs	0.120
Options | Level 3 fair value measurement | Weighted average cost of capital
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Significant unobservable inputs	0.100
Options | Level 3 fair value measurement | Long term growth rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Significant unobservable inputs	0.030