Fair Value of Financial Instruments - Carrying Amounts of Assets and Liabilities at Estimated Fair Value Measured on a Recurring Basis (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	$ 33,095	$ 31,990
Derivative investments	244	816
Total financial assets at fair value	8,169	5,600
Level 1
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	2,286	4,360
Derivative investments	0	0
Short term investments	2,590	168
Total financial assets at fair value	6,210	6,803
Derivatives:
Total financial liabilities at fair value	0	0
Level 2
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	0	0
Derivative investments	244	816
Short term investments	0	2
Total financial assets at fair value	25,720	27,948
Derivatives:
Total financial liabilities at fair value	0	73
Level 3
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	0	0
Derivative investments	0	0
Short term investments	0	321
Total financial assets at fair value	8,169	5,600
Derivatives:
Total financial liabilities at fair value	3,115	3,883
Fair Value Measured at NAV
Assets, Fair Value Disclosure [Abstract]
Total financial assets at fair value	47	48
Total Estimated Fair Value
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents	2,286	4,360
Derivative investments	244	816
Short term investments	2,590	491
Total financial assets at fair value	40,146	40,399
Derivatives:
Total financial liabilities at fair value	3,115	3,956
Reinsurance related embedded derivatives \| Level 1
Assets, Fair Value Disclosure [Abstract]
Derivative investments	0
Derivatives:
Derivative liability		0
Reinsurance related embedded derivatives \| Level 2
Assets, Fair Value Disclosure [Abstract]
Derivative investments	279
Derivatives:
Derivative liability		73
Reinsurance related embedded derivatives \| Level 3
Assets, Fair Value Disclosure [Abstract]
Derivative investments	0
Derivatives:
Derivative liability		0
Reinsurance related embedded derivatives \| Total Estimated Fair Value
Assets, Fair Value Disclosure [Abstract]
Derivative investments	279
Derivatives:
Derivative liability		73
FIA/ IUL embedded derivatives, included in contractholder funds \| Level 1
Derivatives:
Derivative liability	0	0
FIA/ IUL embedded derivatives, included in contractholder funds \| Level 2
Derivatives:
Derivative liability	0	0
FIA/ IUL embedded derivatives, included in contractholder funds \| Level 3
Derivatives:
Derivative liability	3,115	3,883
FIA/ IUL embedded derivatives, included in contractholder funds \| Total Estimated Fair Value
Derivatives:
Derivative liability	3,115	3,883
Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	11,467	8,695
Asset-backed securities \| Level 1
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	0	0
Asset-backed securities \| Level 2
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	5,204	4,736
Asset-backed securities \| Level 3
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	6,263	3,959
Asset-backed securities \| Total Estimated Fair Value
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	11,467	8,695
Commercial mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	3,063	2,979
Commercial mortgage-backed securities \| Level 1
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	0	0
Commercial mortgage-backed securities \| Level 2
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	3,026	2,944
Commercial mortgage-backed securities \| Level 3
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	37	35
Commercial mortgage-backed securities \| Total Estimated Fair Value
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	3,063	2,979
Corporates
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	14,337	16,494
Corporates \| Level 1
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	40	37
Corporates \| Level 2
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	12,857	15,322
Corporates \| Level 3
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	1,440	1,135
Corporates \| Total Estimated Fair Value
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	14,337	16,494
Hybrids
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	731	912
Hybrids \| Level 1
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	93	132
Hybrids \| Level 2
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	638	780
Hybrids \| Level 3
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	0	0
Hybrids \| Total Estimated Fair Value
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	731	912
Municipals \| Level 1
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	0	0
Municipals \| Level 2
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	1,431	1,458
Municipals \| Level 3
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	29	43
Municipals \| Total Estimated Fair Value
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	1,460	1,501
Residential mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	1,527	731
Residential mortgage-backed securities \| Level 1
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	0	0
Residential mortgage-backed securities \| Level 2
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	1,225	731
Residential mortgage-backed securities \| Level 3
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	302	0
Residential mortgage-backed securities \| Total Estimated Fair Value
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	1,527	731
U.S. Government
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	271	394
U.S. Government \| Level 1
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	260	394
U.S. Government \| Level 2
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	11	0
U.S. Government \| Level 3
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	0	0
U.S. Government \| Total Estimated Fair Value
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	271	394
Foreign Governments
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	239	284
Foreign Governments \| Level 1
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	0	0
Foreign Governments \| Level 2
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	223	266
Foreign Governments \| Level 3
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	16	18
Foreign Governments \| Total Estimated Fair Value
Assets, Fair Value Disclosure [Abstract]
Fixed maturity securities available-for-sale	239	284
Equity securities \| Level 1
Assets, Fair Value Disclosure [Abstract]
Equity securities	621	1,206
Equity securities \| Level 2
Assets, Fair Value Disclosure [Abstract]
Equity securities	0	0
Equity securities \| Level 3
Assets, Fair Value Disclosure [Abstract]
Equity securities	10	9
Equity securities \| Fair Value Measured at NAV
Assets, Fair Value Disclosure [Abstract]
Equity securities	47	48
Equity securities \| Total Estimated Fair Value
Assets, Fair Value Disclosure [Abstract]
Equity securities	678	1,263
Preferred securities
Assets, Fair Value Disclosure [Abstract]
Equity securities	903	1,401
Preferred securities \| Level 1
Assets, Fair Value Disclosure [Abstract]
Equity securities	320	506
Preferred securities \| Level 2
Assets, Fair Value Disclosure [Abstract]
Equity securities	582	893
Preferred securities \| Level 3
Assets, Fair Value Disclosure [Abstract]
Equity securities	1	2
Preferred securities \| Total Estimated Fair Value
Assets, Fair Value Disclosure [Abstract]
Equity securities	903	1,401
Other long-term investments \| Level 1
Assets, Fair Value Disclosure [Abstract]
Other long-term investments	0	0
Other long-term investments \| Level 2
Assets, Fair Value Disclosure [Abstract]
Other long-term investments	0	0
Other long-term investments \| Level 3
Assets, Fair Value Disclosure [Abstract]
Other long-term investments	71	78
Other long-term investments \| Total Estimated Fair Value
Assets, Fair Value Disclosure [Abstract]
Other long-term investments	$ 71	$ 78

Short-term Investments, Fair Value

No definition available.

Name:	fnf_ShortTermInvestmentsFairValue
Namespace Prefix:	fnf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

+ Details

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

- References

No definition available.

+ Details

Name:	us-gaap_AssetsFairValueDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

No definition available.

+ Details

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

- Definition

Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454

+ Details

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

- Definition

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 22
-URI https://asc.fasb.org/extlink&oid=99393222&loc=SL20226052-175313

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=123594938&loc=d3e13433-108611

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

+ Details

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

- References

No definition available.

+ Details

Name:	us-gaap_DerivativeAssetsAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=123594938&loc=d3e13433-108611

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 22
-URI https://asc.fasb.org/extlink&oid=99393222&loc=SL20226052-175313

+ Details

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

- Definition

Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as current.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(2))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (f)
-URI https://asc.fasb.org/extlink&oid=124098289&loc=d3e6676-107765

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 1A
-URI https://asc.fasb.org/extlink&oid=123594786&loc=SL75136599-209740

+ Details

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

- Definition

Fair value of financial obligations, including, but not limited to, debt instruments, derivative liabilities, federal funds purchased and sold under agreements to repurchase, securities loaned or sold under agreements to repurchase, financial instruments sold not yet purchased, guarantees, line of credit, loans and notes payable, servicing liability, and trading liabilities.

+ References

No definition available.

+ Details

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

- Definition

Fair value portion of other assets.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=fnf_EmbeddedDerivativesinReinsuranceContractsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=fnf_FixedIndexAnnuityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CommercialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=fnf_HybridsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_ResidentialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_ForeignGovernmentDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_PreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_OtherLongTermInvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: