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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, 2025 | Jun. 30, 2025 | Mar. 31, 2025 | Sep. 30, 2024 | Jun. 30, 2024 | Mar. 31, 2024 | Sep. 30, 2025 | Sep. 30, 2024
Accounts Receivable, Allowance for Credit Loss [Roll Forward] |  |  |  |  |  |  |  |
Current expected credit loss provision |  |  |  |  |  |  | $ 5,404 | $ 4,953
Trade Accounts Receivable |  |  |  |  |  |  |  |
Accounts Receivable, Allowance for Credit Loss [Roll Forward] |  |  |  |  |  |  |  |
Beginning balance | $ 2,035 | $ 3,104 | $ 1,839 | $ 1,897 | $ 2,648 | $ 1,603 | 1,839 | 1,603
Current expected credit loss provision | 2,225 | 27 | 3,152 | 1,850 | 405 | 2,698 |  |
Less write-offs charged against the allowance | 3,142 | 1,335 | 2,305 | 2,715 | 1,432 | 2,114 |  |
Credit loss recoveries collected | 296 | 239 | 418 | 341 | 276 | 461 |  |
Ending balance | 1,414 | 2,035 | 3,104 | 1,373 | 1,897 | 2,648 | 1,414 | 1,373
Electric | Trade Accounts Receivable |  |  |  |  |  |  |  |
Accounts Receivable, Allowance for Credit Loss [Roll Forward] |  |  |  |  |  |  |  |
Beginning balance | 461 | 542 | 473 | 491 | 684 | 414 | 473 | 414
Current expected credit loss provision | 646 | 178 | 939 | 520 | 190 | 782 |  |
Less write-offs charged against the allowance | 688 | 333 | 1,036 | 594 | 463 | 659 |  |
Credit loss recoveries collected | 76 | 74 | 166 | 86 | 80 | 147 |  |
Ending balance | 495 | 461 | 542 | 503 | 491 | 684 | 495 | 503
Natural gas distribution | Trade Accounts Receivable |  |  |  |  |  |  |  |
Accounts Receivable, Allowance for Credit Loss [Roll Forward] |  |  |  |  |  |  |  |
Beginning balance | 1,574 | 2,562 | 1,366 | 1,406 | 1,964 | 1,189 | 1,366 | 1,189
Current expected credit loss provision | 1,579 | (151) | 2,213 | 1,330 | 215 | 1,916 |  |
Less write-offs charged against the allowance | 2,454 | 1,002 | 1,269 | 2,121 | 969 | 1,455 |  |
Credit loss recoveries collected | 220 | 165 | 252 | 255 | 196 | 314 |  |
Ending balance | 919 | 1,574 | 2,562 | 870 | 1,406 | 1,964 | 919 | 870
Pipeline | Trade Accounts Receivable |  |  |  |  |  |  |  |
Accounts Receivable, Allowance for Credit Loss [Roll Forward] |  |  |  |  |  |  |  |
Beginning balance | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0
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 | $ 0 | $ 0 | $ 0 | $ 0 | $ 0

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