Receivables and allowance for expected credit losses - Accounts Receivable, Allowance for Credit Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current expected credit loss provision	$ 2,287	$ 3,765
Trade Accounts Receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	9,570	4,154
Current expected credit loss provision	2,287	3,765
Less write-offs charged against the allowance	2,162	1,943
Credit loss recoveries collected	461	375
Ending balance	10,156	6,351
Electric | Trade Accounts Receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	414	375
Current expected credit loss provision	782	615
Less write-offs charged against the allowance	659	667
Credit loss recoveries collected	147	145
Ending balance	684	468
Natural gas distribution | Trade Accounts Receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1,189	1,615
Current expected credit loss provision	1,916	2,324
Less write-offs charged against the allowance	1,455	1,225
Credit loss recoveries collected	314	229
Ending balance	1,964	2,943
Pipeline | Trade Accounts Receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	0	2
Current expected credit loss provision	0	0
Less write-offs charged against the allowance	0	0
Credit loss recoveries collected	0	0
Ending balance	0	2
Construction services | Trade Accounts Receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	7,967	2,162
Current expected credit loss provision	(411)	826
Less write-offs charged against the allowance	48	51
Credit loss recoveries collected	0	1
Ending balance	$ 7,508	$ 2,938