XML 113 R101.htm IDEA: XBRL DOCUMENT
v3.25.3

Contractholder Funds - Narrative (Details) - USD ($) $ in Millions | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2025 | Dec. 31, 2024
Insurance [Abstract] |  |
Change in contractholder funds | $ 24 | $ 89

X
- Definition Policyholder Account Balance, Increase (Decrease) From Change In Assumptions + References No definition available. + Details
Name: | fnf_PolicyholderAccountBalanceIncreaseDecreaseFromChangeInAssumptions
Namespace Prefix: | fnf_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_InsuranceAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration