Investments and Related Matters Other Segments (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Schedule of Investments [Line Items]
Investments	$ 10,026	$ 15,351
Other Segments [Member]
Schedule of Investments [Line Items]
Investments	755	798
Other Segments [Member] | Equity method investments
Schedule of Investments [Line Items]
Investments	340	323
Other Segments [Member] | Other investments
Schedule of Investments [Line Items]
Investments	$ 415	$ 475