LEASES - Schedule of Lease Expenses (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Leases [Abstract]
Amortization of finance lease asset	$ 3
Interest on lease liabilities	4
Total finance lease expense	7
Operating lease expense	47
Total lease expense	54
Variable lease expense	5
Short-term lease expense	$ 1