Trading Assets and Liabilities - Summary of Trading Assets and Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Trading Assets	$ 355,332	$ 280,195
Trading Liabilities	108,835	108,897
Trading Cash Instruments [Member]
Trading Cash Instruments	310,080	235,349
Trading Liabilities	65,033	66,303
Derivatives [Member]
Trading Assets at Fair Value	45,252	44,846
Trading Liabilities	$ 43,802	$ 42,594

The carrying amount of liabilities as of the balance sheet date that pertain to principal and customer trading transactions, or which may be incurred with the objective of generating a profit from short-term fluctuations in price as part of an entity's market-making, hedging and proprietary trading. Examples include short positions in securities, derivatives and commodities, obligations under repurchase agreements, and securities borrowed arrangements.

No definition available.

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