Fair Value Option- Assets and Liabilities, by Type, of Consolidated Investment Management Funds Recorded at Fair Value (Detail) (Investment Management funds, USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Investment Management funds
Assets of consolidated investment management funds:
Trading assets	$ 8,823	$ 10,397
Other assets	739	875
Subtotal assets of consolidated investment management funds, at fair value	9,562	11,272
Liabilities of consolidated investment management funds:
Trading liabilities	8,130	10,085
Other liabilities	10	46
Subtotal liabilities of consolidated investment management funds, at fair value	$ 8,140	$ 10,131