v3.20.4
HEALTH, SAFETY AND ENVIRONMENTAL MATTERS (Tables)
 12 Months Ended
Dec. 31, 2020
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,
 20202019
 (Thousands of Dollars)
Balance as of the beginning of year$7,938 $7,753 
Additions to accrual3,692 3,700 
Payments(3,257)(3,515)
Balance as of the end of year$8,373 $7,938 
Environmental Accruals By Balance Sheet Location [Table Text Block]
Accruals for environmental matters are included in the consolidated balance sheets as follows:
 December 31,
 20202019
 (Thousands of Dollars)
Accrued liabilities$5,371 $4,837 
Other long-term liabilities3,002 3,101 
Accruals for environmental matters$8,373 $7,938