Contingencies and Commitments (Details) $ in Millions, $ in Millions			1 Months Ended
	Aug. 23, 2019 USD ($)	Dec. 13, 2016 AUD ($)	Sep. 30, 2018 action	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	May 26, 2020 claim	Aug. 31, 2019 USD ($)	Aug. 12, 2016 USD ($)
Loss Contingencies [Line Items]
Number of derivative actions filed | action			11
Claim revenue for costs				$ 215	$ 216
Fluor T E C H I N T | Barrick
Loss Contingencies [Line Items]
Letters of credit outstanding, amount							$ 36
Fluor T E C H I N T | Barrick | Parent Company
Loss Contingencies [Line Items]
Letters of credit outstanding, amount							24
Fluor T E C H I N T | Barrick | Partnership Interest
Loss Contingencies [Line Items]
Letters of credit outstanding, amount							$ 12
Pending litigation
Loss Contingencies [Line Items]
Number of pending matters | claim						1
Damages sought		$ 1,470
Pending litigation | Sadara Chemical Company
Loss Contingencies [Line Items]
Damages sought	$ 100
Estimate of possible loss	$ 574
Pending litigation | Fluor T E C H I N T
Loss Contingencies [Line Items]
Estimate of possible loss				$ 364				$ 250