Represents the increase (decrease) in the estimated project cost based on forecast revisions.

No definition available.

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Namespace Prefix:	flr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the increase (decrease) in estimated petrochemical project cost based on forecast revisions, in dollars per diluted share.

+ References

No definition available.

+ Details

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Namespace Prefix:	flr_
Data Type:	dtr-types1:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Charges From Write-Off of Embedded Foreign Currency Derivatives

+ References

No definition available.

+ Details

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Namespace Prefix:	flr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of foreign currency translation gain (loss) in the disposal group, including discontinued operation, recognized in the statement of income as a result of the sale or complete or substantially complete liquidation of an investment in a foreign entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 830
-SubTopic 30
-Section 45
-Paragraph 20
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481694/830-30-45-20

+ Details

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

- Definition

The difference between the carrying value and the sale price of an investment. A gain would be recognized when the sale price of the investment is greater than the carrying value of the investment. This element refers to the Gain included in earnings and not to the cash proceeds of the sale.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(9)(a))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(7)(c))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-28

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(13))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1

+ Details

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

- Definition

The difference between the carrying value and the sale price of an investment. A loss would be recognized when the sale price of the investment is less than the carrying value of the investment. This element refers to the Loss included in earnings and not to the cash proceeds of the sale.

+ References

+ Details

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

- Definition

The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-12

+ Details

Name:	us-gaap_ProceedsFromDivestitureOfBusinesses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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

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

- Details

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupNotDiscontinuedOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=flr_StorkHoldingBVMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=flr_AMECOMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

Operating Information by Segment and Geographic Area - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended		3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Disposal Group, Not Discontinued Operations \| Stork
Segment Reporting Information [Line Items]
Proceeds from sale	$ 67
Gain on sale					$ 11
Disposal Group, Not Discontinued Operations \| AMECO
Segment Reporting Information [Line Items]
Loss on sale		$ 60
AMECO divestiture, negative impact on earnings from foreign currency translation		$ 35
Energy Solutions
Segment Reporting Information [Line Items]
Effect of forecast revision on estimated project cost				$ 34	$ 39	$ 34
Effect of forecast revision on estimated project cost (in dollars per share)				$ 0.20	$ 0.16	$ 0.20
Expense from embedded foreign currency derivatives			$ 20	$ (8)	$ 27	$ (47)
Urban Solutions \| LAX Automated People Mover Project
Segment Reporting Information [Line Items]
Effect of forecast revision on estimated project cost			$ 59		$ 59
Effect of forecast revision on estimated project cost (in dollars per share)			$ 0.34		$ 0.34
Mission Solutions \| Weapons Facility Project
Segment Reporting Information [Line Items]
Effect of forecast revision on estimated project cost						$ 30
Effect of forecast revision on estimated project cost (in dollars per share)						$ 0.17