INCOME TAXES - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Federal income tax rate	35.00%	35.00%	35.00%
Goodwill not deductible for tax purposes			78.40%
Goodwill impairment, Tax rate	(0.00%)	(0.00%)	35.10%
State operating loss carryforwards	$ 1,900,000,000
Deferred tax asset valuation allowance	123,000,000	$ 157,000,000
Decrease in deferred tax asset valuation allowance	34,000,000
Unrecognized tax benefits that would impact effective tax rate	43,000,000
Interest on unrecognized tax benefits accrued during period	1,000,000	1,000,000	$ 2,000,000
Accrued interest on unrecognized tax benefits	14,000,000	15,000,000	14,000,000
Penalties accrued income tax examination	0	0	0
Penalties expense income tax examination	0	$ 0	$ 0
Decreases for tax positions related to settlements with taxing authorities	4,000,000
Settlement with Taxing Authority
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Anticipated decrease in unrecognized tax benefits due to settlement with taxing authorities	55,000,000
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