Discontinued Operations - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
INCOME TAX EXPENSE	$ 490,077,000	$ 28,710,000	$ 368,289,000	$ 39,260,000
Less: Net earnings attributable to noncontrolling interests from discontinued operations	(2,185,000)	(4,481,000)	(7,803,000)	(9,013,000)
Net earnings (loss) attributable to Fluor Corporation from discontinued operations	39,621,000	8,764,000	69,007,000	104,907,000
Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	791,255,000	815,720,000	2,393,884,000	3,097,217,000
Cost of revenue	764,296,000	778,287,000	2,314,660,000	2,910,459,000
Corporate general and administrative expense	(27,205,000)	2,604,000	(20,005,000)	6,628,000
Interest expense (income), net	(230,000)	(189,000)	(1,381,000)	(490,000)
Total cost and expenses	736,861,000	780,702,000	2,293,274,000	2,916,597,000
Earnings (loss) before taxes from discontinued operations	54,394,000	35,018,000	100,610,000	180,620,000
Income tax expense (benefit)	12,588,000	21,773,000	23,800,000	66,700,000
Net earnings (loss) from discontinued operations	41,806,000	13,245,000	76,810,000	113,920,000
Less: Net earnings attributable to noncontrolling interests from discontinued operations	2,185,000	4,481,000	7,803,000	9,013,000
Net earnings (loss) attributable to Fluor Corporation from discontinued operations	39,621,000	8,764,000	69,007,000	104,907,000
Discontinued Operations | Government
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	718,153,000	754,543,000	2,196,176,000	2,907,000,000
Cost of revenue	693,750,000	718,219,000	2,102,747,000	2,740,053,000
Corporate general and administrative expense	603,000	594,000	2,735,000	3,235,000
Interest expense (income), net	(123,000)	(64,000)	(1,101,000)	(208,000)
Total cost and expenses	694,230,000	718,749,000	2,104,381,000	2,743,080,000
Earnings (loss) before taxes from discontinued operations	23,923,000	35,794,000	91,795,000	163,920,000
Income tax expense (benefit)	5,570,000	23,067,000	21,034,000	64,140,000
Net earnings (loss) from discontinued operations	18,353,000	12,727,000	70,761,000	99,780,000
Less: Net earnings attributable to noncontrolling interests from discontinued operations	2,185,000	4,481,000	7,803,000	9,013,000
Net earnings (loss) attributable to Fluor Corporation from discontinued operations	16,168,000	8,246,000	62,958,000	90,767,000
Discontinued Operations | AMECO
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	73,102,000	61,177,000	197,708,000	190,217,000
Cost of revenue	70,546,000	60,068,000	211,913,000	170,406,000
Corporate general and administrative expense	40,000	87,000	189,000	242,000
Interest expense (income), net	(107,000)	(125,000)	(280,000)	(282,000)
Total cost and expenses	70,479,000	60,030,000	211,822,000	170,366,000
Earnings (loss) before taxes from discontinued operations	2,623,000	1,147,000	(14,114,000)	19,851,000
Income tax expense (benefit)	580,000	(852,000)	(2,535,000)	3,285,000
Net earnings (loss) from discontinued operations	2,043,000	1,999,000	(11,579,000)	16,566,000
Less: Net earnings attributable to noncontrolling interests from discontinued operations	0	0	0	0
Net earnings (loss) attributable to Fluor Corporation from discontinued operations	2,043,000	1,999,000	(11,579,000)	16,566,000
Discontinued Operations | Other
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	0	0	0	0
Cost of revenue	0	0	0	0
Corporate general and administrative expense	(27,848,000)	1,923,000	(22,929,000)	3,151,000
Interest expense (income), net	0	0	0	0
Total cost and expenses	(27,848,000)	1,923,000	(22,929,000)	3,151,000
Earnings (loss) before taxes from discontinued operations	27,848,000	(1,923,000)	22,929,000	(3,151,000)
Income tax expense (benefit)	6,438,000	(442,000)	5,301,000	(725,000)
Net earnings (loss) from discontinued operations	21,410,000	(1,481,000)	17,628,000	(2,426,000)
Less: Net earnings attributable to noncontrolling interests from discontinued operations	0	0	0	0
Net earnings (loss) attributable to Fluor Corporation from discontinued operations	$ 21,410,000	$ (1,481,000)	$ 17,628,000	$ (2,426,000)