Assets and Liabilities Measured at Fair Value (Tables)

12 Months Ended

Dec. 31, 2023

Fair Value Disclosures [Abstract]

Schedule of Carrying Value of Assets and Liabilities Recorded at Fair Value on Recurring Basis

The fair value measurements for these assets and liabilities for the respective periods presented are shown in the following table.

	December 31, 2023								December 31, 2022
(Thousands of dollars)	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Liabilities:
Nonqualified employee savings plan	$	17,785	$	–	$	–	$	17,785	$	15,135	$	–	$	–	$	15,135
	$	17,785	$	–	$	–	$	17,785	$	15,135	$	–	$	–	$	15,135

Schedule of Carrying Amounts and Estimated Fair Values of Financial Instruments

The following table presents the carrying amounts and estimated fair values of financial instruments held by the Company at December 31, 2023 and 2022. The fair value of a financial instrument is the amount at which the instrument could be exchanged in a current transaction between willing parties. The table excludes cash and cash equivalents, trade accounts receivable, trade accounts payable and accrued expenses, all of which had fair values approximating carrying amounts. The fair value of current and long-term debt was estimated based on rates offered to the Company at that time for debt of the same maturities. Substantially all of the Company’s long-term debt is actively traded in open markets, and accordingly, is classified as Level 1 in the fair value

hierarchy. The Company has off-balance sheet exposures relating to certain letters of credit. The fair value of these, which represents fees associated with obtaining the instruments, was nominal.

	December 31,
	2023				2022
(Thousands of dollars)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Financial liabilities:
Current and long-term debt	$	1,329,075	$	1,265,185	$	1,823,139	$	1,668,216