Other Assets (Details 2) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Components of other intangible assets
Gross Carrying Amount	$ 1,737	$ 1,710
Accumulated Amortization	(941)	(856)
Net Carrying Amount	796	854
Other Contracts [Member]
Components of other intangible assets
Gross Carrying Amount	231	255
Accumulated Amortization	(105)	(102)
Customer Relationships [Member]
Components of other intangible assets
Gross Carrying Amount	1,506	1,455
Accumulated Amortization	$ (836)	$ (754)