Presentation Prior Period Adjustment (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease in equity	$ (26,807)	$ (26,145)	$ (17,336)	$ (15,686)
Increase in other liabilities and deferred revenue	40,141	40,886
Increase in deferred income taxes	590	598
Adjustments for Change in accounting principle [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease in equity		271		303
Increase in other liabilities and deferred revenue		424		468
Increase in deferred income taxes		$ 153		$ 165