Investments In and Advances To Affiliates (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Investments in and Advances to Affiliates [Line Items]
Operating margin	$ 574	$ 755	$ 1,083	$ 1,476
Net income (loss)	$ (387)	$ 264	(313)	518
Minority Owned Affiliates [Member]
Investments in and Advances to Affiliates [Line Items]
Revenue			286	357
Operating margin			69	86
Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest			30	35
Parent [Member]
Investments in and Advances to Affiliates [Line Items]
Net income (loss)			$ (356)	$ 211