INCOME TAXES - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
U.S. Federal income tax rate	35.00%	35.00%	35.00%
State operating loss carryforwards	$ 1,400,000,000
Deferred tax asset valuation allowance	107,000,000	$ 123,000,000
Decrease in deferred tax asset valuation allowance	(16,000,000)
Unrecognized tax benefits that would impact effective tax rate	29,000,000
Interest on unrecognized tax benefits accrued during period	8,000,000	1,000,000	$ 1,000,000
Accrued interest on unrecognized tax benefits	22,000,000	14,000,000	15,000,000
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