Variable Interest Entities (Details) (USD $)	3 Months Ended		9 Months Ended				3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 Consolidated variable interest entities	Dec. 31, 2011 Consolidated variable interest entities	Sep. 30, 2012 Fluor Sinclair Knight Merz (SKM) joint venture	Sep. 30, 2011 Fluor Sinclair Knight Merz (SKM) joint venture	Sep. 30, 2012 Fluor Sinclair Knight Merz (SKM) joint venture	Sep. 30, 2011 Fluor Sinclair Knight Merz (SKM) joint venture	Sep. 30, 2012 Unconsolidated variable interest entities	Dec. 31, 2011 Unconsolidated variable interest entities
Variable interest entity information
Maximum Entity's interest in joint venture (as a percent)					50.00%
Investment carrying value, unconsolidated VIEs											$ 71,000,000	$ 50,000,000
Future funding commitments											55,000,000
Carrying value of assets					1,100,000,000	1,100,000,000
Carrying value of liabilities					691,000,000	774,000,000
Revenue	$ 7,136,056,000	$ 6,037,613,000	$ 20,554,413,000	$ 17,129,265,000			$ 1,000,000,000	$ 407,000,000	$ 2,500,000,000	$ 1,300,000,000