Investments In and Advances To Affiliates (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Investments in and Advances to Affiliates [Line Items]
Revenue	$ 4,262	$ 4,150
Operating margin	794	749
Net income	66	199
Minority Owned Affiliates [Member]
Investments in and Advances to Affiliates [Line Items]
Revenue	277	359
Operating margin	77	286
Net income	$ 49	$ (2)