Restatement (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Restatement
Accounts Receivable Payable, Affiliated Companies, Overstated Amount	$ 312
Net Cash Provided by Operating Activities, Overstated Amount	312
Increase In Notes Payable, Affiliated Companies, Understated Amount	312
Net Cash Used in Financing Activites, Overstated Amount	312
Accounts receivable/payable–affiliated companies	(89)	$ 37	$ (5)
Net cash provided by operating activities	895	858	928
Increase in notes payable–affiliated companies	312	(3)	(148)
Net cash used in financing activities	(112)	$ 142	$ (1,812)
Scenario, Previously Reported [Member]
Restatement
Accounts receivable/payable–affiliated companies	223
Net cash provided by operating activities	1,207
Increase in notes payable–affiliated companies	0
Net cash used in financing activities	$ (424)