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| 17.  | Changes in Accumulated Other Comprehensive Income (Loss) by Component |    Changes to accumulated other comprehensive income (loss) by component for the three months ended  March 31, 2023 are as follows:   
|  |  | Unrealized |  |  |  |  |  |  |  |  |  |  
|  |  | Net Gain (Loss) |  |  | Retiree |  |  |  |  |  |  
|  |  | on Interest |  |  | Health |  |  |  |  |  |  
|  |  | Rate |  |  | Benefit |  |  |  |  |  |  
|  |  | Swap |  |  | Obligation |  |  | Total |  |  
| Balance at December 31, 2022 |  | $ | 6,115 |  |  | $ | 3,013 |  |  | $ | 9,128 |  |  
| Other comprehensive loss before reclassifications |  |  | (871 | ) |  |  | — |  |  |  | (871 | ) |  
| Amounts reclassified from accumulated other comprehensive income (loss): (1) |  |  | (665 | ) |  |  | (53 | ) |  |  | (718 | ) |  
| Balance at March 31, 2023 |  | $ | 4,579 |  |  | $ | 2,960 |  |  | $ | 7,539 |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  
| (1) Amounts reclassified from accumulated other comprehensive income (loss): |  |  |  |  |  |  |  |  |  |  |  |  |  
| Amortization of Other Postretirement Benefit items: |  |  |  |  |  |  |  |  |  |  |  |  |  
| Actuarial gains |  | $ | (72 | ) |  |  |  |  |  |  |  |  |  
| Tax expense |  |  | 19 |  |  |  |  |  |  |  |  |  |  
| Reclassification net of tax |  | $ | (53 | ) |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Realized gains on interest rate swaps reclassified to interest expense |  | $ | (899 | ) |  |  |  |  |  |  |  |  |  
| Tax expense |  |  | 234 |  |  |  |  |  |  |  |  |  |  
| Reclassification net of tax |  | $ | (665 | ) |  |  |  |  |  |  |  |  |    Changes to accumulated other comprehensive income (loss) by component for the three months ended  March 31, 2022, are as follows:   
|  |  | Unrealized |  |  |  |  |  |  |  |  |  |  
|  |  | Net Gain (Loss) |  |  | Retiree |  |  |  |  |  |  
|  |  | on Interest |  |  | Health |  |  |  |  |  |  
|  |  | Rate |  |  | Benefit |  |  |  |  |  |  
|  |  | Swap |  |  | Obligation |  |  | Total |  |  
| Balance at December 31, 2021 |  | $ | (3,524 | ) |  | $ | 2,471 |  |  | $ | (1,053 | ) |  
| Other comprehensive gain before reclassifications |  |  | 3,517 |  |  |  | — |  |  |  | 3,517 |  |  
| Amounts reclassified from accumulated other comprehensive income (loss): (1) |  |  | 762 |  |  |  | (41 | ) |  |  | 721 |  |  
| Balance at March 31, 2022 |  | $ | 755 |  |  | $ | 2,430 |  |  | $ | 3,185 |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  
| (1) Amounts reclassified from accumulated other comprehensive income (loss): |  |  |  |  |  |  |  |  |  |  |  |  |  
| Amortization of Other Postretirement Benefit items: |  |  |  |  |  |  |  |  |  |  |  |  |  
| Actuarial gains |  | $ | (55 | ) |  |  |  |  |  |  |  |  |  
| Tax expense |  |  | 14 |  |  |  |  |  |  |  |  |  |  
| Reclassification net of tax |  | $ | (41 | ) |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Realized losses on interest rate swaps reclassified to interest expense |  | $ | 1,030 |  |  |  |  |  |  |  |  |  |  
| Tax benefit |  |  | (268 | ) |  |  |  |  |  |  |  |  |  
| Reclassification net of tax |  | $ | 762 |  |  |  |  |  |  |  |  |  |    |