INCOME TAXES - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
U.S. Federal income tax rate	21.00%	35.00%	35.00%
State operating loss carryforwards	$ 1,400,000,000
Deferred tax asset valuation allowance	110,000,000	$ 105,000,000
Decrease in deferred tax asset valuation allowance	5,000,000
Unrecognized tax benefits that would impact effective tax rate	6,000,000
Interest on unrecognized tax benefits accrued (released) during period	0	8,000,000	$ 8,000,000
Accrued interest on unrecognized tax benefits	2,000,000	1,000,000	22,000,000
Penalties accrued income tax examination	0	0	0
Penalties expense income tax examination	0	$ 0	$ 0
Tax Years Ended Prior to 1988
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Base year loan loss reserves attributable to prior years	$ 557,000,000