Fair Values of Assets and Liabilities (Fair Value of Other Financial Instruments) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Carrying Amount [Member]
Assets
Cash and cash equivalents	$ 29,943	$ 29,189
Cash and investments segregated and on deposit for regulatory purposes	17,440	19,143
Receivables from brokerage clients — net	74,707	64,436
Bank loans – net	25,421	23,813
Other assets	3,063	2,883
Liabilities
Bank deposits	369,898	358,022
Payables to brokerage clients	101,339	104,201
Accrued expenses and other liabilities	9,011	8,263
Short-term borrowings	2,500
Long-term debt	17,584	13,626
Carrying Amount [Member] \| First Mortgage [Member]
Assets
Bank loans – net	15,674	14,882
Carrying Amount [Member] \| HELOCs [Member]
Assets
Bank loans – net	771	837
Carrying Amount [Member] \| Pledged asset lines [Member]
Assets
Bank loans – net	8,797	7,916
Carrying Amount [Member] \| Other [Member]
Assets
Bank loans – net	179	178
Portion at Other than Fair Value Measurement [Member]
Assets
Cash and cash equivalents	29,943	29,189
Cash and investments segregated and on deposit for regulatory purposes	17,440	19,143
Receivables from brokerage clients — net	74,707	64,436
Bank loans – net	25,610	24,237
Other assets	3,063	2,883
Liabilities
Bank deposits	369,898	358,022
Payables to brokerage clients	101,339	104,201
Accrued expenses and other liabilities	9,011	8,263
Short-term borrowings	2,500
Long-term debt	18,360	14,829
Portion at Other than Fair Value Measurement [Member] \| First Mortgage [Member]
Assets
Bank loans – net	15,845	15,305
Portion at Other than Fair Value Measurement [Member] \| HELOCs [Member]
Assets
Bank loans – net	789	838
Portion at Other than Fair Value Measurement [Member] \| Pledged asset lines [Member]
Assets
Bank loans – net	8,797	7,916
Portion at Other than Fair Value Measurement [Member] \| Other [Member]
Assets
Bank loans – net	179	178
Portion at Other than Fair Value Measurement [Member] \| Level 1 [Member]
Assets
Cash and cash equivalents	29,943	29,189
Cash and investments segregated and on deposit for regulatory purposes	4,001	4,212
Receivables from brokerage clients — net	0	0
Bank loans – net	0	0
Other assets	0	0
Liabilities
Bank deposits	0	0
Payables to brokerage clients	0	0
Accrued expenses and other liabilities	0	0
Short-term borrowings	0
Long-term debt	0	0
Portion at Other than Fair Value Measurement [Member] \| Level 1 [Member] \| First Mortgage [Member]
Assets
Bank loans – net	0	0
Portion at Other than Fair Value Measurement [Member] \| Level 1 [Member] \| HELOCs [Member]
Assets
Bank loans – net	0	0
Portion at Other than Fair Value Measurement [Member] \| Level 1 [Member] \| Pledged asset lines [Member]
Assets
Bank loans – net	0	0
Portion at Other than Fair Value Measurement [Member] \| Level 1 [Member] \| Other [Member]
Assets
Bank loans – net	0	0
Portion at Other than Fair Value Measurement [Member] \| Level 2 [Member]
Assets
Cash and cash equivalents	0	0
Cash and investments segregated and on deposit for regulatory purposes	13,439	14,931
Receivables from brokerage clients — net	74,707	64,436
Bank loans – net	25,610	24,237
Other assets	3,063	2,883
Liabilities
Bank deposits	369,898	358,022
Payables to brokerage clients	101,339	104,201
Accrued expenses and other liabilities	9,011	8,263
Short-term borrowings	2,500
Long-term debt	18,360	14,829
Portion at Other than Fair Value Measurement [Member] \| Level 2 [Member] \| First Mortgage [Member]
Assets
Bank loans – net	15,845	15,305
Portion at Other than Fair Value Measurement [Member] \| Level 2 [Member] \| HELOCs [Member]
Assets
Bank loans – net	789	838
Portion at Other than Fair Value Measurement [Member] \| Level 2 [Member] \| Pledged asset lines [Member]
Assets
Bank loans – net	8,797	7,916
Portion at Other than Fair Value Measurement [Member] \| Level 2 [Member] \| Other [Member]
Assets
Bank loans – net	179	178
Portion at Other than Fair Value Measurement [Member] \| Level 3 [Member]
Assets
Cash and cash equivalents	0	0
Cash and investments segregated and on deposit for regulatory purposes	0	0
Receivables from brokerage clients — net	0	0
Bank loans – net	0	0
Other assets	0	0
Liabilities
Bank deposits	0	0
Payables to brokerage clients	0	0
Accrued expenses and other liabilities	0	0
Short-term borrowings	0
Long-term debt	0	0
Portion at Other than Fair Value Measurement [Member] \| Level 3 [Member] \| First Mortgage [Member]
Assets
Bank loans – net	0	0
Portion at Other than Fair Value Measurement [Member] \| Level 3 [Member] \| HELOCs [Member]
Assets
Bank loans – net	0	0
Portion at Other than Fair Value Measurement [Member] \| Level 3 [Member] \| Pledged asset lines [Member]
Assets
Bank loans – net	0	0
Portion at Other than Fair Value Measurement [Member] \| Level 3 [Member] \| Other [Member]
Assets
Bank loans – net	$ 0	$ 0

Cash And Securities Segregated Under Federal And Other Regulations, Fair Value Disclosure

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- Definition

Payables To Customer, Fair Value Disclosure

+ References

No definition available.

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- Definition

Fair value portion of amount due from customers or clients for goods or services, including trade receivables, that have been delivered or sold in the normal course of business, and amounts due from others, including related parties.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13433-108611

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- Definition

Fair value portion of accrued expenses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.20)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

No definition available.

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- Definition

Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

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

- References

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Period Type:	duration

- Definition

Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-URI http://asc.fasb.org/subtopic&trid=2196772

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

- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Fair value portion of other assets.

+ References

No definition available.

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

- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents the amount of short-term debt existing as of the balance sheet date.

+ References

No definition available.

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