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Commitments and Contingent Liabilities - Narrative (Details) $ in Thousands |  | 9 Months Ended |  |
--- | --- | --- | --- | ---
Mar. 13, 2019 USD ($) | Sep. 30, 2021 USD ($) company | Dec. 31, 2020 USD ($) | Jun. 05, 2017 company
Product Liability Contingency |  |  |  |
Litigation settlement amount |  | $ 28,000 |  |
Number of companies that received a general notice letter (company) | company |  |  |  | 140
Present value of remedial work |  | 1,100,000 |  |
Undiscovered remedial work |  | $ 1,700,000 |  |
Anticipated clean period |  | 13 years |  |
Number of potentially responsible parties included in agreement | company |  | 100 |  |
Accrual for environmental loss |  | $ 2,481 | $ 2,562 |
UPRR |  |  |  |
Product Liability Contingency |  |  |  |
Annual commitment amount | $ 8,000 | $ 6,000 |  |
UPRR |  |  |  |
Product Liability Contingency |  |  |  |
Litigation settlement amount | 50,000 |  |  |
Litigation settlement amount, current | 2,000 |  |  |
Litigation settlement amount, non-current | $ 48,000 |  |  |
Payment period | 6 years |  |  |

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