Number of shares of common stock canceled during the period.

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- Definition

The equity interest of noncontrolling shareholders.

+ References

No definition available.

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- Definition

The parent entity's interest in the subsidiary.

+ References

No definition available.

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- Definition

The percentage of combined voting power of common stock.

+ References

No definition available.

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- Definition

The percentage of economic interest in limited liability company.

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No definition available.

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- Definition

The number of shares contributed by the majority owner of the acquiree in the exchange transaction.

+ References

No definition available.

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- 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.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

+ References

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- Definition

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

+ References

No definition available.

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- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

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- Definition

Number of shares of stock issued during the period pursuant to acquisitions.

+ 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(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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Stockholder's Equity - Issuance and Cancellation of Common Stock (Details) - shares		9 Months Ended
	Apr. 08, 2019	Sep. 30, 2020	Sep. 30, 2019
Class A Common Stock
Class of Stock [Line Items]
Number of shares owned	46,000,000	90,985,582
Percentage of combined voting power	2.70%
Class B Common Stock
Class of Stock [Line Items]
Shares contributed by Refinitiv Owner (in shares)	96,933,192
Number of shares owned		96,933,192
Class C Common Stock
Class of Stock [Line Items]
Shares issued to acquire TWM LLC (in shares)	20,000,000
Number of shares canceled (in shares)	9,993,731
Number of shares owned		5,109,991
Class D Common Stock
Class of Stock [Line Items]
Shares issued to acquire TWM LLC (in shares)	105,289,005
Number of shares canceled (in shares)	36,006,269
Number of shares owned		34,403,255
Continuing LLC Owners
Class of Stock [Line Items]
Percentage of combined voting power	27.50%
Continuing LLC Owners \| Class C Common Stock
Class of Stock [Line Items]
Number of shares owned	10,006,269
Continuing LLC Owners \| Class D Common Stock
Class of Stock [Line Items]
Number of shares owned	46,294,407
Refinitiv Direct Owner
Class of Stock [Line Items]
Shares contributed by Refinitiv Owner (in shares)	96,933,192
Number of shares owned	96,933,192
Refinitiv Direct Owner \| Class B Common Stock
Class of Stock [Line Items]
Number of shares owned	96,933,192
Percentage of combined voting power	56.40%
Refinitiv LLC Owner \| Class D Common Stock
Class of Stock [Line Items]
Number of LLC Interest (in shares)	22,988,329
Tradeweb Markets LLC
Class of Stock [Line Items]
Number of LLC Interest (in shares)		39,513,246	79,289,005
Ownership percentage, Continuing LLC Owners		17.40%	35.70%
Number of LLC Interest held by parent (in shares)	142,933,192	187,918,774	142,942,945
Ownership interest	64.30%	82.60%	64.30%
Tradeweb Markets LLC \| Class A Common Stock
Class of Stock [Line Items]
Percentage of economic interest	20.70%
Tradeweb Markets LLC \| Continuing LLC Owners
Class of Stock [Line Items]
Number of LLC Interest (in shares)	56,300,676
Ownership percentage, Continuing LLC Owners	25.30%
Tradeweb Markets LLC \| Refinitiv LLC Owner \| Class B Common Stock
Class of Stock [Line Items]
Percentage of economic interest	43.60%
Tradeweb Markets LLC \| Refinitiv LLC Owner \| Class D Common Stock
Class of Stock [Line Items]
Percentage of combined voting power	10.30%
Number of LLC Interest (in shares)	22,988,329
Ownership percentage, Continuing LLC Owners	13.40%