v3.19.3.a.u2

HEALTH, SAFETY AND ENVIRONMENTAL MATTERS (Tables) | 12 Months Ended
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Dec. 31, 2019
Environmental Remediation Obligations [Abstract] |
Schedule of Environmental Accrual Rollforward [Table Text Block] | The balance of and changes in the accruals for environmental matters were as follows:
| Year Ended December 31,
| 2019 |  | 2018
| (Thousands of Dollars)
Balance as of the beginning of year | $ | 7,753 |  |  | $ | 5,095 |
Additions to accrual | 3,700 |  |  | 5,708 |
Payments | (3,515 | ) |  | (3,050 | )
Balance as of the end of year | $ | 7,938 |  |  | $ | 7,753 |
Environmental Accruals By Balance Sheet Location [Table Text Block] | Accruals for environmental matters are included in the consolidated balance sheets as follows:
| December 31,
| 2019 |  | 2018
| (Thousands of Dollars)
Accrued liabilities | $ | 4,837 |  |  | $ | 4,349 |
Other long-term liabilities | 3,101 |  |  | 3,404 |
Accruals for environmental matters | $ | 7,938 |  |  | $ | 7,753 |

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