Fair Value Measurement- Carrying Amount and Fair Value of Financial Instruments (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Assets:
Loans	$ 79	$ 16
Estimated Fair Value
Assets:
Interest-bearing deposits with the Federal Reserve and other central banks	92,317	104,359
Interest-bearing deposits with banks	30,354	35,323
Federal funds sold and securities purchased under resale agreements	17,375	9,161
Securities held-to-maturity	20,167	19,443
Loans	55,242	49,316
Other financial assets	7,491	7,601
Subtotal assets of consolidated investment management funds, at fair value	222,946	225,203
Liabilities:
Noninterest-bearing deposits	101,105	95,475
Interest-bearing deposits	162,737	165,253
Federal funds purchased and securities sold under repurchase agreements	9,687	9,648
Payables to customers and broker-dealers	20,155	15,707
Borrowings	986	919
Long-term debt	21,669	19,965
Total liabilities	316,339	306,967
Estimated Fair Value | Level 1
Assets:
Securities held-to-maturity	4,149	3,268
Other financial assets	6,410	6,460
Subtotal assets of consolidated investment management funds, at fair value	10,559	9,728
Estimated Fair Value | Level 2
Assets:
Interest-bearing deposits with the Federal Reserve and other central banks	92,317	104,359
Interest-bearing deposits with banks	30,354	35,323
Federal funds sold and securities purchased under resale agreements	17,375	9,161
Securities held-to-maturity	16,018	16,175
Loans	55,242	49,316
Other financial assets	1,081	1,141
Subtotal assets of consolidated investment management funds, at fair value	212,387	215,475
Liabilities:
Noninterest-bearing deposits	101,105	95,475
Interest-bearing deposits	162,737	165,253
Federal funds purchased and securities sold under repurchase agreements	9,687	9,648
Payables to customers and broker-dealers	20,155	15,707
Borrowings	986	919
Long-term debt	21,669	19,965
Total liabilities	316,339	306,967
Carrying Amount
Assets:
Interest-bearing deposits with the Federal Reserve and other central banks	92,317	104,359
Interest-bearing deposits with banks	30,341	35,300
Federal funds sold and securities purchased under resale agreements	17,375	9,161
Securities held-to-maturity	20,137	19,743
Loans	55,164	49,180
Other financial assets	7,491	7,601
Subtotal assets of consolidated investment management funds, at fair value	222,825	225,344
Liabilities:
Noninterest-bearing deposits	101,105	95,475
Interest-bearing deposits	163,791	165,654
Federal funds purchased and securities sold under repurchase agreements	9,687	9,648
Payables to customers and broker-dealers	20,155	15,707
Borrowings	986	919
Long-term debt	21,246	19,543
Total liabilities	$ 316,970	$ 306,946