Business Segment Data - Summary of Operating Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Operating revenue	$ 2,849,685	$ 2,854,390	$ 2,699,250
Cost of sales	2,510,234	2,532,472	2,423,204
Gross profit	339,451	321,918	276,046
Selling, general and administrative expenses	149,544	131,375	111,402
Operating income	189,907	190,543	164,644
Interest expense	14,023	16,954	6,354
Other income	4,875	3,981	1,379
Income before income taxes and income from equity method investments	180,759	177,570	159,669
Operating segments
Segment Reporting Information [Line Items]
Operating revenue	2,868,593	2,869,444	2,715,233
Corporate and Other
Segment Reporting Information [Line Items]
Operating revenue	0	0	0
Cost of sales	2,987	13	169
Gross profit	(2,987)	(13)	(169)
Selling, general and administrative expenses	29,132	17,431	12,483
Operating income	(32,119)	(17,444)	(12,652)
Eliminations
Segment Reporting Information [Line Items]
Operating revenue	(18,908)	(15,054)	(15,983)
E&M
Segment Reporting Information [Line Items]
Operating revenue	2,023,911	2,125,543	1,988,729
E&M | Operating segments
Segment Reporting Information [Line Items]
Operating revenue	2,031,447	2,134,867	1,997,840
Cost of sales	1,804,095	1,911,721	1,816,938
Gross profit	219,816	213,822	171,791
Selling, general and administrative expenses	82,845	79,445	66,830
Operating income	136,971	134,377	104,961
Interest expense	(800)	4,957	2,572
E&M | Eliminations
Segment Reporting Information [Line Items]
Operating revenue	(7,536)	(9,324)	(9,111)
T&D
Segment Reporting Information [Line Items]
Operating revenue	825,774	728,847	710,521
T&D | Operating segments
Segment Reporting Information [Line Items]
Operating revenue	837,146	734,577	717,393
Cost of sales	703,152	620,738	606,097
Gross profit	122,622	108,109	104,424
Selling, general and administrative expenses	37,567	34,499	32,089
Operating income	85,055	73,610	72,335
Interest expense	4,027	4,490	1,406
T&D | Eliminations
Segment Reporting Information [Line Items]
Operating revenue	$ (11,372)	$ (5,730)	$ (6,872)