Operating Information by Segment and Geographic Area - Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Revenue	$ 3,103,085	$ 3,456,938	$ 9,278,017	$ 10,889,575
Total segment profit (loss)	101,565	66,115	88,692	72,471
G&A	(42,371)	(36,697)	(139,439)	(112,853)
Impairment, restructuring and other exit costs	0	0	(26,392)	(106,189)
Foreign currency gain (loss)	37,453	(29,763)	(4,203)	16,197
Earnings (loss) from Cont Ops before taxes	70,195	54,227	29,437	45,543
Continuing Operations
Segment Reporting Information [Line Items]
G&A	(42,400)	(36,700)	(139,400)	(112,900)
Impairment, restructuring and other exit costs	0	0	(26,400)	(106,200)
Foreign currency gain (loss)	37,500	(29,800)	(4,200)	16,200
Interest income (expense), net	(31,400)	(11,900)	(59,300)	(26,900)
Earnings (loss) from Cont Ops attributable to NCI	(3,500)	4,200	21,500	19,700
Earnings (loss) from Cont Ops before taxes	70,200	54,200	29,400	45,500
Continuing Operations | Reportable segments
Segment Reporting Information [Line Items]
Revenue	3,103,100	3,456,900	9,278,000	10,889,600
Total segment profit (loss)	110,000	128,400	237,200	255,600
Continuing Operations | Energy Solutions | Reportable segments
Segment Reporting Information [Line Items]
Revenue	1,365,400	1,337,900	3,675,400	4,195,200
Total segment profit (loss)	72,500	96,200	183,900	133,000
Continuing Operations | Urban Solutions | Reportable segments
Segment Reporting Information [Line Items]
Revenue	1,014,700	1,329,400	3,419,200	4,434,200
Total segment profit (loss)	17,800	29,300	(20,800)	119,200
Continuing Operations | Mission Solutions | Reportable segments
Segment Reporting Information [Line Items]
Revenue	723,000	789,600	2,183,400	2,260,200
Total segment profit (loss)	$ 27,900	$ 24,500	$ 116,500	$ 66,300