The amount of adjustment to additional paid in capital for consulting service fee.

No definition available.

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Namespace Prefix:	tw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of consulting service incurred for follow on offering.

+ References

No definition available.

+ Details

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Namespace Prefix:	tw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of consulting service incurred for IPO.

+ References

No definition available.

+ Details

Name:	tw_ConsultingServiceFeeForIpo
Namespace Prefix:	tw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

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

- 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

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

- Details

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Namespace Prefix:
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Period Type:

- Details

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Namespace Prefix:
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Related Party Transactions - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Related Party Transactions
Consulting service fee for IPO			$ 1.0
Consulting service fee for follow on offering			0.5	$ 0.5
Adjustment to additional paid in capital due to consulting service fee			2.0
Refinitiv \| Operating Expense Reimbursement
Related Party Transactions
Related party expense	$ 0.9	$ 3.2	$ 1.2	$ 4.2