XML 127 R105.htm IDEA: XBRL DOCUMENT
v3.22.4

Employee Benefit Plans (The Weighted-Average Discount Rate Assumptions Used to Determine Net Periodic Benefit Costs) (Detail) - Unfunded Supplemental Benefit Plans | 12 Months Ended
--- | ---
Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Discount rates: |  |  |
Projected benefit obligation | 2.89% | 2.49% | 3.27%
Service cost | 3.29% | 3.14% | 3.71%
Interest cost | 2.37% | 1.83% | 2.86%

X
- Definition Defined benefit plan assumptions used calculating net periodic benefit cost discount rate for interest cost. + References No definition available. + Details
Name: | faf_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRateForInterestCost
Namespace Prefix: | faf_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Defined benefit plan assumptions used calculating net periodic benefit cost discount rate for service cost. + References No definition available. + Details
Name: | faf_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRateForServiceCost
Namespace Prefix: | faf_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine net periodic benefit cost of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(1) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

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

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_SupplementalEmployeeRetirementPlanDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |