Provision (Benefit) for Income Taxes Reconciliations to Recorded Tax Provision (Benefit) Table (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effective Income Tax Rate Reconciliation [Abstract]
Provision (benefit) at statutory rate	$ 69	$ 187	$ (131)
Increases (decreases) in taxes resulting from:
Impact of nontaxable noncontrolling interests	(73)	(117)	(22)
Federal Tax Reform rate change	0	(1,932)	0
State income taxes (net of federal benefit)	(10)	(17)	3
State deferred income tax rate change	38	26	43
Foreign operations – net (including tax effect of Canadian Sale)	0	(127)	78
Valuation allowance	105	0	0
Translation adjustment of certain unrecognized tax benefits	0	0	(1)
Other – net	9	6	5
Provision (benefit) for income taxes	$ 138	$ (1,974)	$ (25)