INCOME TAXES - Federal Tax Reconciliation (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Reconciliation between reported income tax expense (benefit) and income taxes calculated by the statutory federal income tax rate
Tax expense at statutory federal rate of 35%	$ 31	$ 14	$ 77	$ 27
State income taxes, net of federal income tax benefit	3	4	10	11
Tax attributable to noncontrolling interests	(28)	(11)	(75)	(33)
Nondeductible goodwill			29
Nontaxable gains	(1)		(18)
Nondeductible litigation	4		37
Change in tax contingency reserves, including interest	(1)		(4)	1
Amendment of prior-year tax returns				(17)
Other items	2	4	5	$ 11
Income tax expense (benefit)	$ 10	$ 11	$ 61
Statutory federal rate (as a percent)			35.00%