Fair Value Measurements (Parenthetical) (Details) (USD $) In Millions, unless otherwise specified			3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014 Cost and equity method investments [Member]	Mar. 31, 2013 Cost and equity method investments [Member]	Mar. 31, 2014 Long Lived Assets, Including Real Estate [Member]	Mar. 31, 2013 Long Lived Assets, Including Real Estate [Member]	Mar. 31, 2014 Fair Value, Inputs, Level 3 [Member] Cost and equity method investments [Member]	Dec. 31, 2013 Fair Value, Inputs, Level 3 [Member] Cost and equity method investments [Member]	Mar. 31, 2014 Fair Value, Inputs, Level 3 [Member] Long Lived Assets, Including Real Estate [Member]	Dec. 31, 2013 Fair Value, Inputs, Level 3 [Member] Long Lived Assets, Including Real Estate [Member]
Adjustments To Assets Measured At Fair Value On Non Recurring Basis			$ (208)	$ (81)	$ (75)	$ (390)
Fair Value Assets Measured On Non Recurring Basis	$ 730	$ 1,460					$ 354	$ 690	$ 192	$ 1,088