Reportable Segments - Operating performance by segment (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2024 USD ($)	Sep. 30, 2024 USD ($)	Jun. 30, 2024 USD ($)	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Sep. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2024 USD ($) segment	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Operating performance by segment
Revenue	$ 1,741,330	$ 1,649,086	$ 1,563,715	$ 1,412,707	$ 1,515,550	$ 1,529,486	$ 1,413,377	$ 1,256,896	$ 6,366,838	$ 5,715,309	$ 4,420,599
Cost of revenue									$ 5,663,593	$ 5,127,818	$ 3,963,714
Cost of revenue, % of Segment Revenue									89.00%	89.70%	89.70%
Gross profit	$ 184,598	$ 198,561	$ 186,710	$ 133,376	$ 156,600	$ 173,895	$ 157,264	$ 99,732	$ 703,245	$ 587,491	$ 456,885
Gross profit, % of Segment Revenue									11.00%	10.30%	10.30%
Selling, general and administrative expenses									$ 383,351	$ 328,733	$ 281,577
Selling, general, and administrative expenses, % of Segment Revenue									6.00%	5.80%	6.40%
Transaction and related costs									$ 2,442	$ 5,685	$ 20,054
Gain on sale and leaseback transaction											(40,084)
Operating income									$ 317,452	$ 253,073	$ 195,338
Operating income, % of Segment Revenue									5.00%	4.40%	4.40%
Number of reportable segments | segment									2
Operating Segment | Utilities
Operating performance by segment
Revenue									$ 2,439,029	$ 2,410,174	$ 2,033,711
Cost of revenue									$ 2,181,068	$ 2,203,182	$ 1,823,039
Cost of revenue, % of Segment Revenue									89.40%	91.40%	89.60%
Gross profit									$ 257,961	$ 206,992	$ 210,672
Gross profit, % of Segment Revenue									10.60%	8.60%	10.40%
Selling, general and administrative expenses									$ 118,253	$ 117,799	$ 91,726
Selling, general, and administrative expenses, % of Segment Revenue									4.80%	4.90%	4.50%
Operating income									$ 139,708	$ 89,193	$ 118,946
Operating income, % of Segment Revenue									5.70%	3.70%	5.80%
Operating Segment | Energy
Operating performance by segment
Revenue									$ 4,032,035	$ 3,346,170	$ 2,397,351
Cost of revenue									$ 3,586,751	$ 2,965,671	$ 2,151,138
Cost of revenue, % of Segment Revenue									89.00%	88.60%	89.70%
Gross profit									$ 445,284	$ 380,499	$ 246,213
Gross profit, % of Segment Revenue									11.00%	11.40%	10.30%
Selling, general and administrative expenses									$ 150,186	$ 132,576	$ 108,563
Selling, general, and administrative expenses, % of Segment Revenue									3.70%	4.00%	4.50%
Operating income									$ 295,098	$ 247,923	$ 137,650
Operating income, % of Segment Revenue									7.30%	7.40%	5.70%
Corporate and non-allocated costs
Operating performance by segment
Revenue									$ (104,226)	$ (41,035)	$ (10,463)
Cost of revenue									(104,226)	(41,035)	(10,463)
Selling, general and administrative expenses									114,912	78,358	81,288
Transaction and related costs									2,442	5,685	20,054
Gain on sale and leaseback transaction											(40,084)
Operating income									(117,354)	(84,043)	(61,258)
Intersegment eliminations
Operating performance by segment
Revenue									(104,226)	(41,035)	(10,463)
Intersegment eliminations | Utilities
Operating performance by segment
Revenue									104,200	29,900	9,400
Cost of revenue									$ 104,200	29,900	9,400
Intersegment eliminations | Energy
Operating performance by segment
Revenue										11,100	1,100
Cost of revenue										$ 11,100	$ 1,100