Guarantee Arrangements, Pledged Assets and Repurchase Agreements - Summary of Pledged Assets Included in Consolidated Balance Sheet (Detail) - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Interest bearing deposits with banks		$ 1,274	$ 676
Trading assets	[1]	3,323	3,802
Securities available-for-sale	[2]	10,417	11,092
Securities held to maturity		3,718	3,293
Loans	[3]	18,135	17,880
Other assets	[4]	644	1,765
Total		$ 37,511	$ 38,508

[1] Trading assets are primarily pledged against liabilities associated with repurchase agreements.

[2] Securities available-for-sale are primarily pledged against derivatives, public fund deposits, trust deposits and various short-term and long term borrowings, as well as providing capacity for potential secured borrowings from the Federal Home Loan Bank of New York ("FHLB") and the Federal Reserve Bank of New York.

[3] Loans are primarily residential mortgage loans pledged against current and potential borrowings from the FHLB and the Federal Reserve Bank of New York.

[4] Other assets represent cash on deposit with non-banks related to derivative collateral support agreements.