INTANGIBLE ASSETS AND GOODWILL - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Impairment of intangible assets	$ 64
Expected aggregate future amortization expense of intangible assets for 2021	95
Expected aggregate future amortization expense of intangible assets for 2022	95
Expected aggregate future amortization expense of intangible assets for 2023	95
Expected aggregate future amortization expense of intangible assets for 2024	95
Expected aggregate future amortization expense of intangible assets for 2025	$ 95
Minimum
Finite-Lived Intangible Assets [Line Items]
Range of amortization life of intangible assets	15 years
Maximum
Finite-Lived Intangible Assets [Line Items]
Range of amortization life of intangible assets	30 years
Contracts acquired in business combinations and other
Finite-Lived Intangible Assets [Line Items]
Amortization expense of intangible assets	$ 97	$ 105	$ 111