Earnings Per Share - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Amounts attributable to Fluor Corporation:
Net earnings (loss) from continuing operations	$ (781,605,000)	$ 68,581,000	$ (1,424,225,000)	$ 69,680,000
Net earnings from discontinued operations	39,621,000	8,764,000	69,007,000	104,907,000
Net earnings (loss)	$ (741,984,000)	$ 77,345,000	$ (1,355,218,000)	$ 174,587,000
Basic EPS attributable to Fluor Corporation:
Weighted average common shares outstanding (shares)	140,163,000	140,713,000	140,027,000	140,489,000
Earnings (loss) from continuing operations (in dollars per share)	$ (5.57)	$ 0.49	$ (10.17)	$ 0.49
Earnings (loss) from discontinued operations, net of taxes (in dollars per share)	0.28	0.06	0.49	0.75
Net earnings (in dollars per share)	$ (5.29)	$ 0.55	$ (9.68)	$ 1.24
Diluted EPS attributable to Fluor Corporation:
Weighted average common shares outstanding (shares)	140,163,000	140,713,000	140,027,000	140,489,000
Diluted effect:
Employee stock options, restricted stock units and shares and Value Driver Incentive units (in shares)	0	836,000	0	877,000
Weighted average diluted shares outstanding (in shares)	140,163,000	141,549,000	140,027,000	141,366,000
Earnings (loss) from continuing operations (in dollars per share)	$ (5.57)	$ 0.49	$ (10.17)	$ 0.49
Earnings, (loss) from discontinued operations, net of taxes (in dollars per share)	0.28	0.06	0.49	0.74
Net earnings (in dollars per share)	$ (5.29)	$ 0.55	$ (9.68)	$ 1.23
Anti-dilutive securities not included above (in shares)	5,490,000	3,988,000	4,910,000	4,063,000
Employee stock options, restricted stock units and shares, and Value Driver Incentive units
Diluted effect:
Anti-dilutive securities not included above (in shares)	489,000		585,000