Represents redemption notice period to redeem investments in common or collective trusts, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

+ Details

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Namespace Prefix:	flr_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

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- Definition

Percentage of target 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/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(5)(i)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of fair value of investments (categorized by debt securities, equity securities, real estate and other plan assets) to the fair value of plan assets held.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e2446-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Namespace Prefix:
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Retirement Benefits - Target and Weighted Average Actual Allocations and Benefit Pension Plans (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Target allocations and the weighted average actual allocations of plan assets
Weighted average actual allocation (as a percent)	100.00%	100.00%
Debt securities
Target allocations and the weighted average actual allocations of plan assets
Weighted average actual allocation (as a percent)	68.00%	68.00%
Equity securities
Target allocations and the weighted average actual allocations of plan assets
Weighted average actual allocation (as a percent)	25.00%	26.00%
Other
Target allocations and the weighted average actual allocations of plan assets
Weighted average actual allocation (as a percent)	7.00%	6.00%
Minimum \| Debt securities
Target allocations and the weighted average actual allocations of plan assets
Target allocation (as a percent)	65.00%
Minimum \| Equity securities
Target allocations and the weighted average actual allocations of plan assets
Target allocation (as a percent)	20.00%
Minimum \| Other
Target allocations and the weighted average actual allocations of plan assets
Target allocation (as a percent)	0.00%
Maximum \| Debt securities
Target allocations and the weighted average actual allocations of plan assets
Target allocation (as a percent)	75.00%
Maximum \| Equity securities
Target allocations and the weighted average actual allocations of plan assets
Target allocation (as a percent)	30.00%
Maximum \| Other
Target allocations and the weighted average actual allocations of plan assets
Target allocation (as a percent)	10.00%
Defined Benefit Pension Plans \| Non-U.S. \| Direct investment in company common stock or debt securities
Target allocations and the weighted average actual allocations of plan assets
Weighted average actual allocation (as a percent)	0.00%
Defined Benefit Pension Plans \| Maximum \| Common or collective trusts
Target allocations and the weighted average actual allocations of plan assets
Redemption notice period to redeem investments	30 days