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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.

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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.

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- Definition

The entire disclosure of deposits with clearing organizations.

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