Composition of Loans to Banking Clients (Detail) (USD $) In Millions	Sep. 30, 2011		Jun. 30, 2011	Dec. 31, 2010		Sep. 30, 2010	Jun. 30, 2010	Dec. 31, 2009
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to banking clients	$ 9,753	[1]		$ 8,778	[1]
Allowance for loan losses	(53)		(50)	(53)		(50)	(51)	(45)
Total loans to banking clients - net	9,700			8,725
Residential real estate mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to banking clients	5,505	[2]		4,695	[3]
Allowance for loan losses	(38)		(34)	(38)
Home equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to banking clients	3,527	[2]		3,500	[3]
Allowance for loan losses	(15)		(16)	(15)
Personal loans secured by securities
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to banking clients	701			562
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to banking clients	$ 20			$ 21

[1] All loans are collectively evaluated for impairment by loan segment.

[2] The computation of the Origination LTV ratio for a HELOC includes any first lien mortgage outstanding on the same property at the time of origination. At September 30, 2011, $756 million of $3.5 billion in HELOCs were in a first lien position.

[3] The computation of the Origination LTV ratio for a HELOC includes any first lien mortgage outstanding on the same property at the time of origination. At December 31, 2010, $742 million of $3.5 billion in HELOCs were in a first lien position.