Fair Values of Assets and Liabilities (Fair Value Hierarchy for Assets Measured at Fair Value) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities owned	$ 657	$ 516
Securities available for sale	61,366	54,783
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	668	2,174
Investments segregated and on deposit for regulatory purposes	5,285	6,311
Other securities owned	657	516
Securities available for sale	61,366	54,783
Total	67,976	63,784
Fair Value, Measurements, Recurring [Member] | Money market funds [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	641	2,142
Fair Value, Measurements, Recurring [Member] | Commercial paper [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	27	32
Fair Value, Measurements, Recurring [Member] | Certificates of deposit [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Investments segregated and on deposit for regulatory purposes	2,951	4,125
Securities available for sale	1,784	1,534
Fair Value, Measurements, Recurring [Member] | U.S. Government securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Investments segregated and on deposit for regulatory purposes	2,334	2,186
Fair Value, Measurements, Recurring [Member] | Schwab Funds money market funds [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities owned	384	224
Fair Value, Measurements, Recurring [Member] | Equity and bond mutual funds [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities owned	203	215
Fair Value, Measurements, Recurring [Member] | State and municipal debt obligations [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities owned	50	51
Fair Value, Measurements, Recurring [Member] | Equity, U.S. Government and corporate debt, and other securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities owned	20	26
Fair Value, Measurements, Recurring [Member] | Asset-backed securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	20,504	19,366
Fair Value, Measurements, Recurring [Member] | U.S. agency mortgage-backed securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	20,531	18,717
Fair Value, Measurements, Recurring [Member] | Corporate debt securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	9,413	8,045
Fair Value, Measurements, Recurring [Member] | U.S. agency notes [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	5,222	3,795
Fair Value, Measurements, Recurring [Member] | Treasury securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	3,581	2,994
Fair Value, Measurements, Recurring [Member] | Non-agency commercial mortgage-backed securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	316	317
Fair Value, Measurements, Recurring [Member] | Other securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	15	15
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	641	2,142
Other securities owned	588	441
Total	1,229	2,583
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member] | Money market funds [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	641	2,142
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member] | Schwab Funds money market funds [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities owned	384	224
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member] | Equity and bond mutual funds [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities owned	203	215
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member] | Equity, U.S. Government and corporate debt, and other securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities owned	1	2
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	27	32
Investments segregated and on deposit for regulatory purposes	5,285	6,311
Other securities owned	69	75
Securities available for sale	61,366	54,783
Total	66,747	61,201
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | Commercial paper [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	27	32
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | Certificates of deposit [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Investments segregated and on deposit for regulatory purposes	2,951	4,125
Securities available for sale	1,784	1,534
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | U.S. Government securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Investments segregated and on deposit for regulatory purposes	2,334	2,186
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | State and municipal debt obligations [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities owned	50	51
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | Equity, U.S. Government and corporate debt, and other securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Other securities owned	19	24
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | Asset-backed securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	20,504	19,366
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | U.S. agency mortgage-backed securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	20,531	18,717
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | Corporate debt securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	9,413	8,045
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | U.S. agency notes [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	5,222	3,795
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | Treasury securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	3,581	2,994
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | Non-agency commercial mortgage-backed securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	316	317
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | Other securities [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	$ 15	$ 15