Summary of Significant Accounting Policies (Details) (USD $)	12 Months Ended
	Dec. 31, 2011 D Y M	Dec. 31, 2010	Dec. 31, 2009
Principles of Consolidation
Minimum percentage of voting interest required to be held to consolidate an entity	50.00%
Maximum percentage of voting interest required to be held to be accounted for, under the cost method	20.00%
Cash and cash equivalents
Cash equivalents maximum maturity period (in days)	90
Financing Receivables
Period of non payment after which a loan is placed on nonaccrual status (in days)	90
Period for charging off revolving unsecured consumer lines, including credit card loans (in days)	180
Period for charging off closed-end consumer loans, other than loans secured by one to four family properties (in days)	120
Restricted and segregated cash and investments
Restricted cash	$ 79,000,000	$ 110,000,000
Amounts segregated under federal and other regulations	1,700,000,000	1,700,000,000
Land, Buildings, Equipment and Software
Amortization periods, low end of the range (in years)	3
Amortization periods, high end of the range (in years)	30
Land, buildings, equipment and software, net of accumulated depreciation	774,000,000	693,000,000
Accumulated depreciation	1,100,000,000	1,100,000,000
Depreciation and amortization expense for the year	143,000,000	160,000,000	176,000,000
Deferred Acquisition Costs
Mean reversion process, period (in years)	5
Income Taxes
Maximum period for recognizing capital losses (in years)	5
Valuation allowance	$ 5,000,000
Sources of Revenue
Rolling performance period for PIA (Performance Incentive Adjustment) (in months)	12
Maximum
Equity Method Investments
Percentage of voting interest required to be held to be accounted for under the equity method	50.00%
Minimum
Equity Method Investments
Percentage of voting interest required to be held to be accounted for under the equity method	20.00%