Other Assets - Other Assets (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Other Assets [Abstract]
Property, leasehold improvements and equipment	$ 13,372	$ 12,070
Goodwill and identifiable intangible assets	4,067	4,095
Income tax-related assets	5,592	5,550
Equity-method investments	221	219
Miscellaneous receivables and other	3,592	3,547
Total	$ 26,844	$ 25,481