INCOME TAXES - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Increase (decrease) in valuation allowance	$ 187	$ (1)
Valuation allowance for deferred tax assets	252	$ 65
Federal
Operating Loss Carryforwards [Line Items]
Gross net operating losses	106
State
Operating Loss Carryforwards [Line Items]
Gross net operating losses	$ 2,900