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Accounting Policies - CECL Table (Details 2) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Accounts Receivable, Credit Loss Expense (Reversal) | $ 1,085 | $ 10,576 | $ 7,864
Trade Accounts Receivable |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Allowance for doubtful accounts | 9,716 | 15,358 | 8,497
Accounts Receivable, Credit Loss Expense (Reversal) | 1,105 | 10,985 |
Accounts Receivable, Allowance for Credit Loss, Writeoff | 8,069 | 5,306 |
Accounts Receivable, Allowance for Credit Loss, Recovery | 1,322 | 1,182 |
Electric | Trade Accounts Receivable |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Allowance for doubtful accounts | 269 | 899 | 328
Accounts Receivable, Credit Loss Expense (Reversal) | 1,099 | 1,517 |
Accounts Receivable, Allowance for Credit Loss, Writeoff | 2,139 | 1,289 |
Accounts Receivable, Allowance for Credit Loss, Recovery | 410 | 343 |
Natural gas distribution | Trade Accounts Receivable |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Allowance for doubtful accounts | 1,506 | 2,571 | 1,056
Accounts Receivable, Credit Loss Expense (Reversal) | 2,188 | 3,187 |
Accounts Receivable, Allowance for Credit Loss, Writeoff | 4,072 | 2,511 |
Accounts Receivable, Allowance for Credit Loss, Recovery | 819 | 839 |
Pipeline | Trade Accounts Receivable |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Allowance for doubtful accounts | 2 | 2 | 0
Accounts Receivable, Credit Loss Expense (Reversal) | 0 | 2 |
Accounts Receivable, Allowance for Credit Loss, Writeoff | 0 | 0 |
Accounts Receivable, Allowance for Credit Loss, Recovery | 0 | 0 |
Construction materials and contracting | Trade Accounts Receivable |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Allowance for doubtful accounts | 5,406 | 6,164 | 5,357
Accounts Receivable, Credit Loss Expense (Reversal) | 68 | 1,447 |
Accounts Receivable, Allowance for Credit Loss, Writeoff | 826 | 640 |
Accounts Receivable, Allowance for Credit Loss, Recovery | 0 | 0 |
Construction services | Trade Accounts Receivable |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Allowance for doubtful accounts | 2,533 | 5,722 | $ 1,756
Accounts Receivable, Credit Loss Expense (Reversal) | (2,250) | 4,832 |
Accounts Receivable, Allowance for Credit Loss, Writeoff | 1,032 | 866 |
Accounts Receivable, Allowance for Credit Loss, Recovery | $ 93 | $ 0 |

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