INCOME TAXES - Federal Tax Reconciliation (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
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 21%	$ 45	$ 32	$ 63	$ 50
State income taxes, net of federal income tax benefit	10	6	15	9
Tax benefit attributable to noncontrolling interests	(16)	(19)	(30)	(36)
Nontaxable gains	0	0	3	(1)
Stock-based compensation	0	1	0	0
Change in valuation allowance	2	11	(88)	35
Other items	4	2	7	(4)
Income tax expense (benefit)	$ 45	$ 33	$ (30)	$ 53