Fair Value Option- Assets and Liabilities, by Type, of Consolidated Investment Management Funds Recorded at Fair Value (Detail) (Investment Management, USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Investment Management
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading assets	$ 10,725	$ 10,961
Other assets	966	520
Subtotal assets of consolidated investment management funds, at fair value	11,691	11,481
Trading liabilities	10,380	10,152
Other liabilities	78	29
Subtotal liabilities of consolidated investment management funds, at fair value	$ 10,458	$ 10,181