OTHER ASSETS - Schedule of Other Assets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Equity method investments	$ 459	$ 72
Other equity investments	52	45
Post-retirement plan assets	38	28
Other	64	40
Total other assets	$ 613	$ 185