VARIABLE INTEREST ENTITIES - Narrative (Details) - LIHTC Investments - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Variable Interest Entity [Line Items]
Amortization method qualified affordable housing project investments, amortization	$ 16,000,000	$ 12,000,000	$ 31,000,000	$ 24,000,000
Affordable housing tax credits and other tax benefits, amount	14,000,000	12,000,000	29,000,000	23,000,000
Other tax expense (benefit)	(7,000,000)	(5,000,000)	(13,000,000)	(9,000,000)
Net impairment losses recognized in earnings	$ 0	$ 0	$ 0	$ 0