Short-Term Borrowings - Short-Term Borrowings (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Debt Disclosure [Abstract]
Other secured financings (short-term)	$ 15,188	$ 14,233
Unsecured short-term borrowings	42,825	42,787
Total	$ 58,013	$ 57,020