Number of capital units or capital shares outstanding. This element is relevant to issuers of face-amount certificates and registered investment companies.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-04.16(a))
-URI http://asc.fasb.org/extlink&oid=120401414&loc=d3e603758-122996

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- 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

- Definition

Face amount or stated value per share of common stock.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

+ References

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

+ References

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Carrying amount as of the balance sheet date of obligations due all related parties. For classified balance sheets, represents the current portion of such liabilities (due within one year or within the normal operating cycle if longer).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k)(1))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(a))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Cash received on stock transaction after deduction of issuance costs.

+ References

No definition available.

+ Details

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

- Details

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Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassBMember
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Balance Type:
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- Details

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

Name:	us-gaap_CapitalUnitsByClassAxis=zi_CommonUnitsMember
Namespace Prefix:
Data Type:	na
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Data Type:	na
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- Details

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Members' Deficit (Details) - USD ($)	2 Months Ended
Members' Deficit (Details) - USD ($)	Dec. 31, 2019	Jun. 30, 2020	Nov. 14, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Related party payable	$ 700,000	$ 0
Class A common stock
Class of Stock [Line Items]
Number of shares authorized	1,000		1,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Number of shares issued	0		0
Class B common stock
Class of Stock [Line Items]
Number of shares authorized	1,000		1,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Number of shares issued	100		100
Consideration received in exchange for shares	$ 1.00
DiscoverOrg Holdings
Class of Stock [Line Items]
Related party payable	$ 700,000			$ 0
Common Units \| DiscoverOrg Holdings
Class of Stock [Line Items]
Number of Units outstanding (in shares)	244,100,000			246,000,000.0
Class P Units \| DiscoverOrg Holdings
Class of Stock [Line Items]
Number of Units outstanding (in shares)	17,200,000			5,700,000
Preferred Units \| DiscoverOrg Holdings
Class of Stock [Line Items]
Number of Units outstanding (in shares)	96,000,000.0			96,000,000.0