Business Segment Data - Summary of Segment Operating Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Segment Reporting Information [Line Items]
Operating revenue	$ 760,985	$ 717,406	$ 2,090,047	$ 2,218,672
Operating segments
Segment Reporting Information [Line Items]
Operating revenue	765,399	721,361	2,105,555	2,229,661
Eliminations
Segment Reporting Information [Line Items]
Operating revenue	(4,414)	(3,955)	(15,508)	(10,989)
Electrical & Mechanical
Segment Reporting Information [Line Items]
Operating revenue	534,741	514,378	1,476,151	1,672,948
Electrical & Mechanical | Operating segments
Segment Reporting Information [Line Items]
Operating revenue	536,895	516,933	1,481,778	1,680,210
Electrical & Mechanical | Eliminations
Segment Reporting Information [Line Items]
Operating revenue	(2,154)	(2,555)	(5,627)	(7,262)
Transmission & Distribution
Segment Reporting Information [Line Items]
Operating revenue	226,244	203,028	613,896	545,724
Transmission & Distribution | Operating segments
Segment Reporting Information [Line Items]
Operating revenue	228,504	204,428	623,777	549,451
Transmission & Distribution | Eliminations
Segment Reporting Information [Line Items]
Operating revenue	$ (2,260)	$ (1,400)	$ (9,881)	$ (3,727)