v3.20.2

Derivatives and Hedging Activities - Outstanding Interest Rate Derivatives Designated as Cash Flow Hedges of Interest Rate Risk (Details) - Designated as Hedging Instrument $ in Millions | Jun. 30, 2020 USD ($) instrument | Dec. 31, 2019 USD ($) instrument | Apr. 30, 2019 USD ($) instrument
--- | --- | --- | ---
Cash Flow Hedging |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Notional Aggregate Principal Amount | $ | $ 850.0 |  |
Interest rate cap contract | Cash Flow Hedging |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Number of Instruments | instrument | 1 |  | 1
Notional Aggregate Principal Amount | $ | $ 406.4 |  | $ 500.0
Interest Cap (as a percent) | 3.50% |  |
Interest rate cap contract | Cash Flow Hedging | DiscoverOrg Holdings |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Number of Instruments | instrument |  | 1 |
Notional Aggregate Principal Amount | $ |  | $ 500.0 | $ 500.0
Interest Cap (as a percent) |  | 3.50% |
Interest rate swap contracts | DiscoverOrg Holdings |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Number of Instruments | instrument |  |  | 2
Interest rate swap contracts | Cash Flow Hedging |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Number of Instruments | instrument | 2 |  | 2
Notional Aggregate Principal Amount | $ | $ 350.0 |  | $ 350.0
Swap Rate (as a percent) | 2.301% |  |
Interest rate swap contracts | Cash Flow Hedging | DiscoverOrg Holdings |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Number of Instruments | instrument |  | 2 |
Notional Aggregate Principal Amount | $ |  | $ 350.0 | $ 350.0
Swap Rate (as a percent) |  | 2.301% |

X
- Definition Average fixed interest rate related to the group of interest rate derivatives. + References No definition available. + Details
Name: | us-gaap_DerivativeAverageFixedInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Cap rate on an interest rate derivative such as an interest rate cap or collar. If market rates exceed the cap rate, a payment or receipt is triggered on the contract. + References No definition available. + Details
Name: | us-gaap_DerivativeCapInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5580258-113959 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5579245-113959 + Details
Name: | us-gaap_DerivativeNotionalAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of derivative instruments of a particular group held by the entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5579245-113959 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5580258-113959 + Details
Name: | us-gaap_DerivativeNumberOfInstrumentsHeld
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

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

X
- Details
Name: | us-gaap_HedgingDesignationAxis=us-gaap_DesignatedAsHedgingInstrumentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateCapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |