Incremental Assets and Liabilities of VIEs Included in Consolidated Financial Statements (Detail) (Variable Interest Entity, Primary Beneficiary, USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Variable Interest Entity [Line Items]
Available-for-sale	$ 485	$ 479
Trading assets	11,079	10,751
Other assets	530	596
Total assets	12,094	11,826
Trading liabilities	10,290	10,053
Other liabilities	475	475
Total liabilities	10,765	10,528
Non-redeemable noncontrolling interests	709	670
Investment Management Funds
Variable Interest Entity [Line Items]
Trading assets	11,079	10,751
Other assets	530	596
Total assets	11,609	11,347
Trading liabilities	10,290	10,053
Other liabilities	38	32
Total liabilities	10,328	10,085
Non-redeemable noncontrolling interests	709	670
Securitizations
Variable Interest Entity [Line Items]
Available-for-sale	485	479
Total assets	485	479
Other liabilities	437	443
Total liabilities	$ 437	$ 443