Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Amounts Attributable to Parent, Disclosures [Abstract]
Net earnings (loss) from Cont Ops attributable to Fluor	$ 22	$ 42	$ 136	$ (127)
Less: Dividends on CPS	10	10	29	15
Net earnings (loss) from Cont Ops available to Fluor common stockholders	12	32	107	(142)
Net earnings (loss) from Disc Ops attributable to Fluor	0	(1)	0	(34)
Net earnings (loss) available to Fluor common stockholders	$ 12	$ 31	$ 107	$ (176)
Weighted average common shares outstanding (shares)	142	141	142	141
Diluted effect:
CPS (in shares)	0	0	0	0
Stock options, RSUs performance-based award units (in shares)	3	2	2	0
Weighted average diluted shares outstanding (in shares)	145	143	144	141
Basic EPS available to Fluor common stockholders:
Net earnings (loss) from Cont Ops (in dollars per share)	$ 0.08	$ 0.23	$ 0.75	$ (1.00)
Net earnings (loss) from Disc Ops (in dollars per share)	0	(0.01)	0	(0.24)
Diluted EPS available to Fluor common stockholders:
Net earnings (loss) from Cont Ops (in dollars per share)	0.08	0.22	0.74	(1.00)
Net earnings (loss) from Disc Ops (in dollars per share)	$ 0	$ (0.01)	$ 0	$ (0.24)