Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended								1 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010	Feb. 28, 2008	Jun. 30, 2011 Other Auction Rate Securities Claims	Dec. 31, 2010 Other Auction Rate Securities Claims	May 31, 2009 Overdrafts Fee Cases LegalMatter	May 31, 2009 Trust Preferred Securities LegalMatter	Nov. 30, 2009 Collateralized Debt Obligations	Jun. 30, 2011 Lower Limit	Jun. 30, 2011 Upper Limit
Aggregate range of reasonably possible losses on legal matters in excess of the accrued liability												$ 95	$ 205
Reserved for the remaining probable loss that could be reasonably estimated							8	24
Accrued fines for settlement with FINRA	5		5				13
Total amount of ARS the Company has purchased	617		617
Cumulative losses on ARS	111		111
Fair value of ARS purchased pursuant to the pending settlement, trading securities	54		54		147
Fair value of ARS purchased pursuant to the pending settlement, available for sale securities	107		107		128
Total gain (loss) relating to the ARS agreements recognized	5	(2)	35	6
Auction rate securities par amount at the time of the collapse of the auction rate market						152
Auction rate securities accrued and settled			14
Number of putative class actions									2	3
Amount sold of an asset that is now related to a loss contingency										690	7
Complaint allegations											the security has lost over $5 million in value
Complaint seeks aggregate damages from all defendants											$ 132