F&G Insurance Subsidiary Financial Information and Regulatory Matters - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Insurance [Abstract]
Permitted practice, statutory surplus	$ 29	$ 102

Statutory Accounting Practices, Permitted Practice, Statutory Surplus, Amount

No definition available.

Name:	fnf_StatutoryAccountingPracticesPermittedPracticeStatutorySurplusAmount
Namespace Prefix:	fnf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant