Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Amounts Attributable to Parent, Disclosures [Abstract]
Net earnings (loss) from Cont Ops attributable to Fluor	$ 48	$ (86)
Less: Dividends on CPS	10	0
Net earnings (loss) from Cont Ops available to Fluor common stockholders	38	(86)
Net earnings (loss) from Disc Ops attributable to Fluor	0	(1)
Net earnings (loss) available to Fluor common stockholders	$ 38	$ (87)
Weighted average common shares outstanding (shares)	142	141
Dilutive effect:
CPS (in shares)	0	0
Stock options, RSU's, Restricted stock and performance-based award units (in shares)	0	0
Weighted average diluted shares outstanding (in shares)	142	141
Basic EPS available to Fluor common stockholders:
Net earnings (loss) from Cont Ops (in dollars per share)	$ 0.27	$ (0.61)
Net earnings (loss) from Disc Ops (in dollars per share)	0	(0.01)
Diluted EPS available to Fluor common stockholders:
Net earnings (loss) from Cont Ops (in dollars per share)	0.27	(0.61)
Net earnings (loss) from Disc Ops (in dollars per share)	$ 0	$ (0.01)