XML 22 R14.htm IDEA: XBRL DOCUMENT
v3.19.2

Deposits With Clearing Organizations | 12 Months Ended
--- | ---
Dec. 31, 2018
Tradeweb Markets LLC |
Entity Information [Line Items] |
Deposits with Clearing Organizations | 6. Deposits with Clearing Organizations Deposits with clearing organizations are comprised of cash deposits. Due to the short-term nature of these deposits, the recorded value has been determined to approximate fair value.

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: | dei_EntityInformationLineItems
Namespace Prefix: | dei_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The entire disclosure of deposits with clearing organizations. + References No definition available. + Details
Name: | tw_DepositsWithClearingOrganizationsTextBlock
Namespace Prefix: | tw_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | dei_LegalEntityAxis=tw_TradewebMarketsLlcMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |