Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Income Amounts Attributable to Parent, Disclosures [Abstract]
Net earnings (loss) attributable to Fluor	$ 61	$ 66	$ (46)	$ 114
Less: Dividends on CPS	10	10	20	20
Net earnings (loss) available to Fluor common stockholders, basic	$ 51	$ 56	$ (66)	$ 94
Weighted average common shares outstanding (shares)	143	142	143	142
Diluted effect:
CPS (in shares)	27	27	0	0
Stock options, RSUs performance-based award units (in shares)	2	3	0	2
Weighted average diluted shares outstanding (in shares)	172	172	143	144
EPS available to Fluor common stockholders, basic (in dollars per share)	$ 0.36	$ 0.40	$ (0.46)	$ 0.67
EPS available to Fluor common stockholders, diluted (in dollars per share)	$ 0.35	$ 0.38	$ (0.46)	$ 0.66