CONSOLIDATED STATEMENT OF OPERATIONS - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Statement [Abstract]
Revenue	$ 15,503	$ 16,315	$ 15,474
Cost of revenue	(15,623)	(15,741)	(14,997)
Gross profit (loss)	(120)	574	477
G&A	(196)	(203)	(232)
Foreign currency gain (loss)	(62)	92	(98)
Operating profit (loss)	(378)	463	147
Interest expense	(42)	(46)	(60)
Interest income	109	196	228
Earnings (loss) before taxes	(311)	613	315
Income tax benefit (expense) (including $92 million and $(376) million attributable to equity method earnings in 2025 and 2024, respectively)	39	(634)	(236)
Net earnings (loss) before equity method earnings	(272)	(21)	79
Equity method earnings	210	2,105	0
Net earnings (loss)	(62)	2,084	79
Less: Net earnings (loss) attributable to NCI	(11)	(61)	(60)
Net earnings (loss) attributable to Fluor	(51)	2,145	139
Less: Dividends on CPS	0	0	29
Less: Make-whole payment on conversion of CPS	0	0	27
Net earnings (loss) available to Fluor common stockholders, basic	(51)	2,145	83
Net earnings (loss) available to Fluor common stockholders, diluted	$ (51)	$ 2,145	$ 83
Basic EPS available to Fluor common stockholders (in dollars per share)	$ (0.31)	$ 12.48	$ 0.55
Diluted EPS available to Fluor common stockholders (in dollars per share)	$ (0.31)	$ 12.30	$ 0.54

Income (Loss) from Continuing Operations, Net of Tax, Before Equity Method Investments, Noncontrolling Interest

No definition available.

Name:	flr_IncomeLossFromContinuingOperationsNetOfTaxBeforeEquityMethodInvestmentsNoncontrollingInterest
Namespace Prefix:	flr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.