Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Valuation Allowance [Line Items]
Deferred tax assets, net	$ 315,000,000	$ 343,000,000
Decrease in deferred tax liability due to investments unrealized losses	89,000,000
Decrease in deferred tax asset, reinsurance receivable	322,000,000
Decrease in deferred tax asset related to life insurance receivables	96,000,000
Operating loss carryforwards	25,000,000
Tax credits	204,000,000	119,000,000
Valuation allowance	164,000,000	197,000,000
Bermuda corporate income tax net operating loss carryforward	10,000,000	24,000,000
Unrecognized tax benefits	0	0
Income taxes receivable	20,000,000	26,000,000
F& G Subsidiaries
Valuation Allowance [Line Items]
Deferred tax assets, net	295,000,000	372,000,000
Income taxes receivable	6,000,000	$ 28,000,000
General Business Credit Carryforward
Valuation Allowance [Line Items]
Valuation allowance	30,000,000
Bermuda Corporate Income Tax Net Operating Loss Carryforward
Valuation Allowance [Line Items]
Valuation allowance, decrease	14,000,000
Deferred Tax Asset, Capital Loss
Valuation Allowance [Line Items]
Valuation allowance	119,000,000
Valuation allowance, decrease	20,000,000
Begin to expire in 2023
Valuation Allowance [Line Items]
Operating loss carryforwards	547,000,000
Title
Valuation Allowance [Line Items]
Decrease in deferred tax liability due to investments unrealized losses	26,000,000
Operating loss carryforwards	44,000,000
Operating loss carryforwards, valuation allowance	25,000,000
Title \| Deferred Tax Asset, Capital Loss
Valuation Allowance [Line Items]
Valuation allowance	71,000,000
Title \| General Business Credit Carryforward
Valuation Allowance [Line Items]
Tax credits	30,000,000
F&G
Valuation Allowance [Line Items]
Decrease in deferred tax liability due to investments unrealized losses	63,000,000
Increase in deferred tax liability, deferred acquisition costs	182,000,000
Increase deferred tax liability, reinsurance receivable	324,000,000
Deferred tax assets, tax credit carryforwards increase	85,000,000
Operating loss carryforwards	503,000,000
F&G \| Deferred Tax Asset, Capital Loss
Valuation Allowance [Line Items]
Valuation allowance	48,000,000
F&G \| General Business Credit Carryforward
Valuation Allowance [Line Items]
Tax credits	$ 164,000,000

Deferred Tax Asset, Foreign DTA For Corporate Income Tax (CIT), NOL Carry Forward, 2023 Tax Act

No definition available.

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

- Definition

Deferred Tax Assets, Tax Credit Carryforwards Increase (Decrease)

+ References

No definition available.

+ Details

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

- Definition

Increase (Decrease) Deferred Tax Asset, Reinsurance Receivable

+ References

No definition available.

+ Details

Name:	fnf_IncreaseDecreaseDeferredTaxAssetReinsuranceReceivable
Namespace Prefix:	fnf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Increase (Decrease) Deferred Tax Liability, Reinsurance Receivable

+ References

No definition available.

+ Details

Name:	fnf_IncreaseDecreaseDeferredTaxLiabilityReinsuranceReceivable
Namespace Prefix:	fnf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Increase (Decrease) in Deferred Tax Asset, Life Insurance Receivables

+ References

No definition available.

+ Details

Name:	fnf_IncreaseDecreaseInDeferredTaxAssetLifeInsuranceReceivables
Namespace Prefix:	fnf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Increase (Decrease) in Deferred Tax Liabilities, Deferred Policy Acquisition Costs and Deferred Sales Inducements

+ References

No definition available.

+ Details

Name:	fnf_IncreaseDecreaseInDeferredTaxLiabilitiesDeferredPolicyAcquisitionCostsAndDeferredSalesInducements
Namespace Prefix:	fnf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Increase (Decrease) In Deferred Tax Liabilities, Investments, Unrealized Gains

+ References

No definition available.

+ Details

Name:	fnf_IncreaseDecreaseInDeferredTaxLiabilitiesInvestmentsUnrealizedGains
Namespace Prefix:	fnf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, without jurisdictional netting.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

+ Details

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

- Definition

Amount, before allocation of a valuation allowances, of deferred tax assets attributable to deductible tax credit carryforwards including, but not limited to, research, foreign, general business, alternative minimum tax, and other deductible tax credit carryforwards.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-6

+ Details

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

- Definition

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

+ Details

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

- Definition

Carrying amount as of the balance sheet date of income taxes previously overpaid to tax authorities (such as U.S. Federal, state and local tax authorities) representing refunds of overpayments or recoveries based on agreed-upon resolutions of disputes. Also called income tax refund receivable.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3)(a)(4))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

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

- Definition

Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-3

+ Details

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

- Definition

The portion of the valuation allowance pertaining to the deferred tax asset representing potential future taxable deductions from net operating loss carryforwards for which it is more likely than not that a tax benefit will not be realized.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

+ Details

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

- Definition

Amount of unrecognized tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 217
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482663/740-10-55-217

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-15A

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 10B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482525/740-10-45-10B

+ Details

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

- Definition

Amount of increase (decrease) in the valuation allowance for a specified deferred tax asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

+ Details

Name:	us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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

- Details

Name:	us-gaap_SubsegmentsAxis=fnf_FGSubsidiariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ValuationAllowanceByDeferredTaxAssetAxis=us-gaap_GeneralBusinessMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ValuationAllowanceByDeferredTaxAssetAxis=fnf_BermudaCorporateIncomeTaxNetOperatingLossCarryforwardMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ValuationAllowanceByDeferredTaxAssetAxis=fnf_DeferredTaxAssetCapitalLossMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TaxPeriodAxis=us-gaap_EarliestTaxYearMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=fnf_TitleSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TaxCreditCarryforwardAxis=us-gaap_GeneralBusinessMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=fnf_FGSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: