Segment Information - Summarized Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Revenues	$ 3,112,800	$ 3,352,895	$ 2,839,199	$ 2,807,259	$ 3,112,218	$ 2,985,281	$ 2,656,348	$ 2,417,576	$ 12,112,153	$ 11,171,423	$ 9,466,478
Operating income (loss)									554,874	540,269	378,849
Depreciation									218,107	202,519	183,808
Operating Segments | Electric Power Infrastructure Services
Segment Reporting Information [Line Items]
Revenues									7,121,837	6,415,562	5,599,836
Operating income (loss)									591,177	628,286	518,130
Depreciation									108,295	96,300	91,708
Operating Segments | Pipeline and Industrial Infrastructure Services
Segment Reporting Information [Line Items]
Revenues									4,990,316	4,755,861	3,866,642
Operating income (loss)									332,011	204,178	184,083
Depreciation									90,953	89,046	76,355
Corporate and Non-Allocated
Segment Reporting Information [Line Items]
Operating income (loss)									(368,314)	(292,195)	(323,364)
Depreciation									$ 18,859	$ 17,173	$ 15,745