Operating Revenues - Contract Liabilities (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Contract liabilities	$ 986.9	$ 883.8
Overall change in contract liability balances	103.1
Deferred new billings	632.4
Operating revenue recognized	530.2
Previously deferred revenue recognized	292.8
Other decreases	$ 0.9

Contract With Customer, Liability, Increase From New Billings

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Contract With Customer, Liability, Net Other Activity

+ References

No definition available.

+ Details

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Namespace Prefix:	clgx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Contract with Customer, Liability, Change In Balance

+ References

No definition available.

+ Details

Name:	clgx_ContractwithCustomerLiabilityChangeInBalance
Namespace Prefix:	clgx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121556615&loc=SL49130531-203044

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130549-203045

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121556615&loc=SL49130532-203044

+ Details

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

- Definition

Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130549-203045

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

Amount of revenue recognized that was previously reported as deferred or unearned revenue.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

+ Details

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