Investments In and Advances To Affiliates (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Investments in and Advances to Affiliates [Line Items]
Operating margin	$ 504	$ 721
Net income	74	254
Minority Owned Affiliates [Member]
Investments in and Advances to Affiliates [Line Items]
Revenue	134	184
Operating margin	35	56
Net income	15	36
Parent [Member]
Investments in and Advances to Affiliates [Line Items]
Net income	$ 126	$ 142