Employee Incentive, Retirement, Deferred Compensation, and Career Achievement Plans (Acquisition of TD Ameritrade Narrative) (Details) - TD Ameritrade [Member] $ in Millions	Oct. 06, 2020 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Conversion of shares (in shares)	1.0837
Fair value of replaced TD Ameritrade equity awards attributable to pre-combination services	$ 94
Remaining portion of value	$ 73
Remaining weighted-average period for unrecognized compensation cost	1 year 10 months 24 days

Business Acquisition, Equity Interest Issued or Issuable, Shares, Conversion

No definition available.

Name:	schw_BusinessAcquisitionEquityInterestIssuedOrIssuableSharesConversion
Namespace Prefix:	schw_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Business Acquisition, Equity Interest Issued or Issuable, Value Assigned, Pre-Combination Services

+ References

No definition available.

+ Details

Name:	schw_BusinessAcquisitionEquityInterestIssuedOrIssuableValueAssignedPreCombinationServices
Namespace Prefix:	schw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of cost to be recognized for option under share-based payment arrangement.

+ References

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_BusinessAcquisitionAxis=schw_TDAmeritradeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: