Incremental Assets and Liabilities of VIEs Included in Consolidated Financial Statements (Detail) (Variable Interest Entity, Primary Beneficiary, USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Variable Interest Entity [Line Items]
Available-for-sale	$ 495	$ 479
Trading assets	10,399	10,751
Other assets	556	596
Total assets	11,450	11,826
Trading liabilities	9,752	10,053
Other liabilities	495	475
Total liabilities	10,247	10,528
Non-redeemable noncontrolling interests	722	670
Investment Management Funds
Variable Interest Entity [Line Items]
Trading assets	10,399	10,751
Other assets	556	596
Total assets	10,955	11,347
Trading liabilities	9,752	10,053
Other liabilities	38	32
Total liabilities	9,790	10,085
Non-redeemable noncontrolling interests	722	670
Securitizations
Variable Interest Entity [Line Items]
Available-for-sale	495	479
Total assets	495	479
Other liabilities	457	443
Total liabilities	$ 457	$ 443