XML 73 R65.htm IDEA: XBRL DOCUMENT v3.19.2

Shares (Details) - Tradeweb Markets LLC - shares	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Successor | Recapitalization
Shares
Number of Vested Shares Issued, Recapitalization	222,222,197
Successor | Class A common stock
Shares
Number of Vested Shares Issued	146,333
Successor | Class A common stock | Recapitalization
Shares
Number of Vested Shares Issued, Recapitalization	203,245,361
Successor | Class C common stock
Shares
Number of Vested Shares Issued	447	447
Successor | Class C common stock | Recapitalization
Shares
Number of Vested Shares Issued, Recapitalization	612,431
Successor | Class P(A) Shares
Shares
Number of Vested Shares Issued	6,887
Successor | Class P(A) Shares | Recapitalization
Shares
Number of Vested Shares Issued, Recapitalization	9,565,659
Successor | Class P(C) Shares
Shares
Number of Vested Shares Issued	2	2
Successor | Class P(C) Shares | Recapitalization
Shares
Number of Vested Shares Issued, Recapitalization	2,520
Successor | Class P-1(A) Shares
Shares
Number of Vested Shares Issued	6,094
Successor | Class P-1(A) Shares | Recapitalization
Shares
Number of Vested Shares Issued, Recapitalization	8,464,589
Successor | Class P-1(C) Shares
Shares
Number of Vested Shares Issued	232	232
Successor | Class P-1(C) Shares | Recapitalization
Shares
Number of Vested Shares Issued, Recapitalization	322,637
Predecessor | Class A common stock
Shares
Number of Vested Shares Issued			146,333
Predecessor | Class A common stock | Recapitalization
Shares
Number of Vested Shares Issued, Recapitalization			203,245,361
Predecessor | Class C common stock
Shares
Number of Vested Shares Issued		447	447	504	528
Predecessor | Class C common stock | Recapitalization
Shares
Number of Vested Shares Issued, Recapitalization			621,431
Predecessor | Class P(A) Shares
Shares
Number of Vested Shares Issued			6,887
Predecessor | Class P(A) Shares | Recapitalization
Shares
Number of Vested Shares Issued, Recapitalization			9,565,659
Predecessor | Class P(C) Shares
Shares
Number of Vested Shares Issued		2	2	2	2
Predecessor | Class P(C) Shares | Recapitalization
Shares
Number of Vested Shares Issued, Recapitalization			2,520
Predecessor | Class P-1(C) Shares
Shares
Number of Vested Shares Issued		232	0	0	0

X

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

X

- Definition

Number of common units issued of limited liability company (LLC).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

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=27012166&loc=d3e187085-122770

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055

+ Details

Name:	us-gaap_CommonUnitIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The number of securities classified as temporary equity that have been issued and are held by the entity's shareholders. Securities outstanding equals securities issued minus securities held in treasury. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer.

+ 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(27)(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_TemporaryEquitySharesOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

X

- Details

Name:	dei_LegalEntityAxis=tw_TradewebMarketsLlcMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementScenarioAxis=tw_AdjustedForRefinitivTransactionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_TypeOfArrangementAxis=tw_LimitedLiabilityCompanyAgreementRecapitalizationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementClassOfStockAxis=tw_CommonClassPaSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementClassOfStockAxis=tw_CommonClassPcSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementClassOfStockAxis=tw_CommonClassP1aSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementClassOfStockAxis=tw_CommonClassP1cSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementScenarioAxis=us-gaap_PredecessorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: