Investments and Related Matters Other Segments (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Schedule of Investments [Line Items]
Investments	$ 9,875	$ 15,351
Other Segments [Member]
Schedule of Investments [Line Items]
Investments	658	798
Other Segments [Member] | Equity method investments
Schedule of Investments [Line Items]
Investments	293	323
Other Segments [Member] | Other investments
Schedule of Investments [Line Items]
Investments	$ 365	$ 475