Receivables and allowance for expected credit losses - Schedule of Accounts Receivable, Allowance for Credit Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Current expected credit loss provision	$ 3,152	$ 2,698
Trade Accounts Receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1,839	1,603
Current expected credit loss provision	3,152	2,698
Less write-offs charged against the allowance	2,305	2,114
Credit loss recoveries collected	418	461
Ending balance	3,104	2,648
Electric | Trade Accounts Receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	473	414
Current expected credit loss provision	939	782
Less write-offs charged against the allowance	1,036	659
Credit loss recoveries collected	166	147
Ending balance	542	684
Natural gas distribution | Trade Accounts Receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1,366	1,189
Current expected credit loss provision	2,213	1,916
Less write-offs charged against the allowance	1,269	1,455
Credit loss recoveries collected	252	314
Ending balance	2,562	1,964
Pipeline | Trade Accounts Receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	0	0
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	$ 0