Fair Value Hierarchy for Assets and Liabilities Measured at Fair Value (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities owned	$ 593	[1]	$ 337	[1]
Securities available for sale	33,965		23,993
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	822		1,230
Investments segregated and on deposit for regulatory purposes	3,791		7,095
Other securities owned	593		337
Securities available for sale	33,965		23,993
Total	39,171		32,655
Fair Value, Measurements, Recurring | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	8		988
Fair Value, Measurements, Recurring | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	814		242
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	2,374		2,201
Securities available for sale	3,622		1,875
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	767		1,704
Securities available for sale	3,571		2,268
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		3,190
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	332		172
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		99
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	46		47
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	32		19
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	20,921		13,098
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	907		1,470
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	1,800		2,780
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	3,144
Fair Value, Measurements, Recurring | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale			2,502
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	8		988
Other securities owned	527		272
Total	535		1,260
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	8		988
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Schwab Funds money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities owned	332		172
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Equity and bond mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities owned	183		99
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | 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	12		1
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	814		242
Investments segregated and on deposit for regulatory purposes	3,791		7,095
Other securities owned	66		65
Securities available for sale	33,965		23,993
Total	38,636		31,395
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	814		242
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments segregated and on deposit for regulatory purposes	2,374		2,201
Securities available for sale	3,622		1,875
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments segregated and on deposit for regulatory purposes	767		1,704
Securities available for sale	3,571		2,268
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | 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		3,190
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | State and municipal debt obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities owned	46		47
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | 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	20		18
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | U.S. agency residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	20,921		13,098
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Non-agency residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	907		1,470
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | U.S. agency notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	1,800		2,780
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Asset-backed and other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	3,144
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale			$ 2,502

[1] Securities pledged were not material at December 31, 2011 or 2010.