INCOME TAXES - Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits, start	$ 2	$ 2
Additions	0	0
Reductions	0	0
Unrecognized tax benefits, end	$ 2	$ 2