LEASES - Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating Lease, Payments	$ 9	$ 10
Finance Lease, Principal Payments	$ 7	$ 6
Weighted average remaining operating lease term (in years)	11 years 4 months 24 days	11 years 10 months 24 days
Weighted average remaining financing lease term (in years)	31 years 1 month 6 days	32 years 3 months 18 days
Weighted average discount rate operating leases (percent)	4.58%	4.64%
Weighted average discount rate financing leases (percent)	5.06%	5.05%