Derivatives and Hedging Activities - Derivatives with Credit-Related Contingent Features (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Derivative [Line Items]
Aggregate fair value of derivative contracts which are in net liability position	$ 28,517	$ 32,927
Aggregate fair value of assets as a collateral for derivative contracts	24,530	27,840
One-Notch Reduction [Member]
Derivative [Line Items]
Additional collateral or termination payments pursuant to bilateral agreements with certain counterparties which could have been called by counterparties in the event of a reduction in the firm's long-term credit ratings	367	677
Two-Notch Reduction [Member]
Derivative [Line Items]
Additional collateral or termination payments pursuant to bilateral agreements with certain counterparties which could have been called by counterparties in the event of a reduction in the firm's long-term credit ratings	$ 1,880	$ 2,216