v3.26.1
DERIVATIVE FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS (Tables)
 3 Months Ended
Mar. 31, 2026
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]  
Fair Value Measurements, Recurring and Nonrecurring
The following tables summarize, by level within the fair value hierarchy, our derivative and other assets and liabilities that were accounted for at fair value on a recurring basis at March 31, 2026 and December 31, 2025:

March 31, 2026
Level 1Level 2Netting (c)Total
(Thousands of dollars)
Assets:
United States treasury notes (b)$7,381 $— $— $7,381 
Corporate bonds (b)— 17,971 — 17,971 
Marketable equity securities (d)2,506 — — 2,506 
Total assets$9,887 $17,971 $— $27,858 
Liabilities:
Derivative instruments - swaps (a)$— $— $— $— 
(a) The fair value is included in other current assets and other current liabilities in our consolidated balance sheets.
(b) The fair value is included in other current and noncurrent assets in our consolidated balance sheets.
(c) Our over-the-counter natural gas fixed-price swaps are presented on a net basis when the right of offset exists.
(d) The fair value is included in other current assets in our consolidated balance sheets.

December 31, 2025
Level 1Level 2Netting (c)Total
(Thousands of dollars)
Assets:
United States treasury notes (b)$9,329 $— $— $9,329 
Corporate bonds (b)— 18,643 — 18,643 
Marketable equity securities (d)2,627 — — 2,627 
Total assets$11,956 $18,643 $— $30,599 
Liabilities:
Derivative instruments - swaps (a)$— $7,309 $— $7,309 
(a) The fair value is included in other current assets and other current liabilities in our consolidated balance sheets.
(b) The fair value is included in other current and noncurrent assets in our consolidated balance sheets.
(c) Our over-the-counter natural gas fixed-price swaps are presented on a net basis when the right of offset exists.
(d) The fair value is included in other current assets in our consolidated balance sheets.