Defined Benefit Plan, Required Contributions By Employer

No definition available.

Name:	ferg_DefinedBenefitPlanRequiredContributionsByEmployer
Namespace Prefix:	ferg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Defined Benefit Plan, Required Contributions By Employer, Payments

+ References

No definition available.

+ Details

Name:	ferg_DefinedBenefitPlanRequiredContributionsByEmployerPayments
Namespace Prefix:	ferg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements payable beyond one year (or the operating cycle, if longer).

+ References

No definition available.

+ Details

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

- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements payable within one year (or the operating cycle, if longer). Represents currently earned compensation under compensation arrangements that is not actually paid until a later date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 710
-SubTopic 10
-Name Accounting Standards Codification
-Section 25
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483070/710-10-25-9

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 710
-SubTopic 10
-Section 30
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483043/710-10-30-2

+ Details

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

- Definition

Carrying amount as of the balance sheet date of assets held under deferred compensation agreements.

+ 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(17))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

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

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

- Definition

Amount of contributions received and expected to be received by defined benefit plan from employer in current fiscal year.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 18
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480482/715-20-55-18

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-6

+ Details

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

- Definition

Percentage of actual investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

+ Details

Name:	us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 70
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480794/715-70-50-1

+ Details

Name:	us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementScenarioAxis=srt_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=ferg_DefinedBenefitPlanGuaranteedInsurancePoliciesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanSponsorLocationAxis=country_GB
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Retirement benefit obligations - Narrative (Details) £ in Millions, $ in Millions	12 Months Ended
	Jul. 31, 2025 GBP (£)	Jul. 31, 2025 USD ($)	Jul. 31, 2024 USD ($)	Jul. 31, 2023 USD ($)	Jul. 31, 2026 USD ($)	Sep. 09, 2025 GBP (£)	Jul. 31, 2025 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Required contributions by employer (in GBP) \| £	£ 133
Payments made of required contributions by employer (in GBP) \| £	£ 72
Percentage of plan assets	100.00%		100.00%				100.00%
Total expense defined contribution plan		$ 98	$ 95	$ 93
Deferred compensation liability, classified, noncurrent			378				$ 408
Deferred compensation liability, current			28				35
Deferred compensation plan assets			$ 373				$ 409
Subsequent Event
Defined Benefit Plan Disclosure [Line Items]
Expected employer contributions \| £						£ 41
Forecast
Defined Benefit Plan Disclosure [Line Items]
Expected employer contributions					$ 59
Insurance policies
Defined Benefit Plan Disclosure [Line Items]
Percentage of plan assets	33.00%		33.00%				33.00%
Insurance policies \| U.K. Plan assets:
Defined Benefit Plan Disclosure [Line Items]
Percentage of plan assets	35.00%						35.00%