INCOME TAXES INCOME TAXES - UNCERTAIN TAX POSITIONS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 29
Income Tax Examination, Penalties and Interest Accrued	6	$ 7		$ 6
Income Tax Examination, Penalties and Interest Expense	(1)	1	$ 1
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities	4	0	1
Beginning balance	40	40	43
Additions related to prior years	1	0	1
Releases related to prior years	(1)	(1)	(4)
Additions related to current year activity	0	2	2
Releases due to settlements	(4)	0	(1)
Releases due to lapse of statute of limitations	(1)	(1)	(1)
Ending balance	35	$ 40	$ 40
State [Member]
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities	5
Releases due to settlements	$ (5)