Receivables and allowance for expected credit losses - Schedule of Accounts Receivable, Allowance for Credit Loss (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current expected credit loss provision							$ 4,902	$ 9,769
Trade Accounts Receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 9,153	$ 10,156	$ 9,570	$ 6,873	$ 6,351	$ 4,154	9,570	4,154
Current expected credit loss provision	1,934	681	2,287	3,907	2,097	3,765
Less write-offs charged against the allowance	2,799	1,973	2,162	3,357	1,873	1,943
Credit loss recoveries collected	384	289	461	308	298	375
Ending balance	8,672	9,153	10,156	7,731	6,873	6,351	8,672	7,731
Electric | Trade Accounts Receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	491	684	414	413	468	375	414	375
Current expected credit loss provision	520	190	782	513	182	615
Less write-offs charged against the allowance	594	463	659	572	316	667
Credit loss recoveries collected	86	80	147	75	79	145
Ending balance	503	491	684	429	413	468	503	429
Natural gas distribution | Trade Accounts Receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1,405	1,964	1,189	1,740	2,943	1,615	1,189	1,615
Current expected credit loss provision	1,330	214	1,916	1,661	90	2,324
Less write-offs charged against the allowance	2,121	969	1,455	2,758	1,454	1,225
Credit loss recoveries collected	255	196	314	233	161	229
Ending balance	869	1,405	1,964	876	1,740	2,943	869	876
Pipeline | Trade Accounts Receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	0	0	0	2	2	2	0	2
Current expected credit loss provision	0	0	0	0	0	0
Less write-offs charged against the allowance	0	0	0	0	0	0
Credit loss recoveries collected	0	0	0	0	0	0
Ending balance	0	0	0	2	2	2	0	2
Construction services | Trade Accounts Receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	7,257	7,508	7,967	4,718	2,938	2,162	7,967	2,162
Current expected credit loss provision	84	277	(411)	1,733	1,825	826
Less write-offs charged against the allowance	84	541	48	27	103	51
Credit loss recoveries collected	43	13	0	0	58	1
Ending balance	$ 7,300	$ 7,257	$ 7,508	$ 6,424	$ 4,718	$ 2,938	$ 7,300	$ 6,424