Leases - Additional Details Related to Leases Recorded on the Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Assets
Operating lease right-of-use assets, net	$ 59.8	$ 32.0
Liabilities
Current portion of operating lease liabilities	8.1	6.0
Operating lease liabilities, net of current portion	$ 61.5	$ 33.6

Present value of lessee's discounted obligation for lease payments from operating lease, classified as current.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123391704&loc=SL77918627-209977

+ Details

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

- Definition

Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent.

+ References

+ Details

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

- Definition

Amount of lessee's right to use underlying asset under operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123391704&loc=SL77918627-209977

+ Details

Name:	us-gaap_OperatingLeaseRightOfUseAsset
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Assets, Lessee

+ References

No definition available.

+ Details

Name:	zi_AssetsLesseeAbstract
Namespace Prefix:	zi_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Liabilities, Lessee

+ References

No definition available.

+ Details

Name:	zi_LiabilitiesLesseeAbstract
Namespace Prefix:	zi_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration