Geographic Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Total Operating Revenue	$ 9,076	$ 10,490	$ 9,707	$ 8,500	$ 8,602	$ 9,923	$ 9,732	$ 8,413	$ 37,773	$ 36,670	$ 35,115
Domestic [Member]
Total Operating Revenue									24,857	23,989	22,722
Atlantic [Member]
Total Operating Revenue									6,446	6,329	6,486
Pacific [Member]
Total Operating Revenue									4,086	4,198	3,644
Latin America [Member]
Total Operating Revenue									$ 2,384	$ 2,154	$ 2,263