v2.4.0.6
Fair Value Hierarchy for Assets and Liabilities Measured at Fair Value (Detail) (USD $)
In Millions, unless otherwise specified
Sep. 30, 2012
Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other securities owned $ 513 $ 593
Securities available for sale 42,448 33,965
Fair Value, Measurements, Recurring
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents 1,084 822
Investments segregated and on deposit for regulatory purposes 3,210 3,791
Other securities owned 513 593
Securities available for sale 42,448 33,965
Total 47,255 39,171
Fair Value, Measurements, Recurring | Money market funds
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents 218 8
Fair Value, Measurements, Recurring | Commercial paper
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents 866 814
Fair Value, Measurements, Recurring | Certificates of deposit
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments segregated and on deposit for regulatory purposes 2,675 2,374
Securities available for sale 5,536 3,622
Fair Value, Measurements, Recurring | Corporate debt securities
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments segregated and on deposit for regulatory purposes 535 767
Securities available for sale 5,610 3,571
Fair Value, Measurements, Recurring | Schwab Funds money market funds
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other securities owned 244 332
Fair Value, Measurements, Recurring | Equity and bond mutual funds
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other securities owned 183 183
Fair Value, Measurements, Recurring | State and municipal debt obligations
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other securities owned 55 46
Fair Value, Measurements, Recurring | Equity, U.S. Government and corporate debt, and other securities
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other securities owned 31 32
Fair Value, Measurements, Recurring | U.S. agency residential mortgage-backed securities
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale 23,772 20,921
Fair Value, Measurements, Recurring | Non-agency residential mortgage-backed securities
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale 782 907
Fair Value, Measurements, Recurring | Commercial paper
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale 449 225
Fair Value, Measurements, Recurring | U.S. agency notes
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale 350 1,800
Fair Value, Measurements, Recurring | U.S. Government securities
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments segregated and on deposit for regulatory purposes   650
Fair Value, Measurements, Recurring | Asset-backed and other securities
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale 5,949 2,919
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents 218 8
Other securities owned 428 527
Total 646 535
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | Money market funds
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents 218 8
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | Schwab Funds money market funds
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other securities owned 244 332
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | Equity and bond mutual funds
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other securities owned 183 183
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | Equity, U.S. Government and corporate debt, and other securities
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other securities owned 1 12
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents 866 814
Investments segregated and on deposit for regulatory purposes 3,210 3,791
Other securities owned 85 66
Securities available for sale 42,448 33,965
Total 46,609 38,636
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Commercial paper
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash equivalents 866 814
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Certificates of deposit
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments segregated and on deposit for regulatory purposes 2,675 2,374
Securities available for sale 5,536 3,622
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Corporate debt securities
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments segregated and on deposit for regulatory purposes 535 767
Securities available for sale 5,610 3,571
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | State and municipal debt obligations
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other securities owned 55 46
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Equity, U.S. Government and corporate debt, and other securities
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other securities owned 30 20
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | U.S. agency residential mortgage-backed securities
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale 23,772 20,921
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Non-agency residential mortgage-backed securities
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale 782 907
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Commercial paper
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale 449 225
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | U.S. agency notes
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale 350 1,800
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | U.S. Government securities
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments segregated and on deposit for regulatory purposes   650
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Asset-backed and other securities
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Securities available for sale $ 5,949 $ 2,919