XML 63 R55.htm IDEA: XBRL DOCUMENT
v3.19.2

Software Development Cost (Details) - Tradeweb Markets LLC - USD ($) | 3 Months Ended | 9 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Dec. 31, 2018 | Sep. 30, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Oct. 01, 2018
Successor |  |  |  |  |
Software Development Cost |  |  |  |  |
Software development costs | $ 175,656,000 |  |  |  |
Accumulated amortization | (5,074,000) |  |  |  |
Software development costs, net of accumulated amortization | 170,582,000 |  |  |  |
Software development costs capitalized | 7,156,000 |  |  |  |
Fair value assigned to software development costs as a result of the Refinitiv Transaction |  |  |  |  | $ 168,500,000
Amortization expense | $ 5,074,000 |  |  |  |
Predecessor |  |  |  |  |
Software Development Cost |  |  |  |  |
Software development costs |  |  | $ 218,382,000 |  |
Accumulated amortization |  |  | (177,201,000) |  |
Software development costs, net of accumulated amortization |  |  | 41,181,000 |  |
Software development costs capitalized |  | $ 19,523,000 | 27,157,000 | $ 25,351,000 |
Amortization expense |  | $ 19,962,000 | $ 25,420,000 | $ 26,824,000 |

X
- Definition Amount of software development costs at the acquisition date. + References No definition available. + Details
Name: | tw_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedSoftwareDevelopmentCosts
Namespace Prefix: | tw_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition n/a + References No definition available. + Details
Name: | tw_SoftwareDevelopmentCostsAbstract
Namespace Prefix: | tw_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition For each balance sheet presented, the amount of accumulated amortization for capitalized computer software costs. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 985 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756 + Details
Name: | us-gaap_CapitalizedComputerSoftwareAccumulatedAmortization
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Additions made to capitalized computer software costs during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275 + Details
Name: | us-gaap_CapitalizedComputerSoftwareAdditions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of expense for amortization of capitalized computer software costs. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 985 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 985 -SubTopic 20 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128487-111756 + Details
Name: | us-gaap_CapitalizedComputerSoftwareAmortization1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount before accumulated amortization of capitalized costs for computer software, including but not limited to, acquired and internally developed computer software. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 985 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756 + Details
Name: | us-gaap_CapitalizedComputerSoftwareGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The carrying amount of capitalized computer software costs net of accumulated amortization as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 985 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756 + Details
Name: | us-gaap_CapitalizedComputerSoftwareNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_StatementScenarioAxis=us-gaap_PredecessorMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |