Segment Information - Summary of segment's internal financial reports (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Segment Reporting Information [Line Items]
Contract revenues:	$ 799,848	$ 610,182	$ 2,144,586	$ 1,852,241
Income from operations:	26,975	30,952	78,122	88,028
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Income from operations:	(18,216)	(18,488)	(49,911)	(51,644)
T&D
Segment Reporting Information [Line Items]
Contract revenues:	452,014	306,546	1,232,105	948,285
T&D | Operating Segments
Segment Reporting Information [Line Items]
Income from operations:	34,315	35,301	97,555	96,737
C&I
Segment Reporting Information [Line Items]
Contract revenues:	347,834	303,636	912,481	903,956
C&I | Operating Segments
Segment Reporting Information [Line Items]
Income from operations:	$ 10,876	$ 14,139	$ 30,478	$ 42,935