Collateralized Agreements and Financings - Additional Information (Detail) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Collateralized Agreements And Financings [Abstract]
Nonrecourse obligations included in other secured financings	$ 2,620	$ 2,200

Amount of debt for which creditor does not have general recourse to the debtor but rather has recourse only to the property used for collateral in the transaction or other specific property.

No definition available.

Name:	us-gaap_NonRecourseDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant