Financial Instruments and Risk Management (Tables)

12 Months Ended

Dec. 31, 2022

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Fair Value of Derivative Instruments Not Designated as Hedging Instruments

At December 31, 2022 and 2021, the fair value of derivative instruments not designated as hedging instruments are presented in the following table. See also Note P.

(Thousands of dollars)	Asset (Liability) Derivatives Fair Value at December 31,
Type of Derivative Contract	Balance Sheet Location	2022	2021
Commodity swaps	Accounts payable	—	(239,882)
Commodity collars	Accounts receivable	—	4,280
	Accounts payable	—	(19,533)

Recognized Gains and Losses for Derivative Instruments Not Designated as Hedging Instruments

For the years ended December 31, 2022, 2021 and 2020, the gains and losses recognized in the Consolidated Statements of Operations for derivative instruments not designated as hedging instruments are presented in the following table.

		Gain (Loss)
(Thousands of dollars)		Year Ended December 31,
Type of Derivative Contract	Statement of Operations Locations	2022		2021		2020
Commodity swaps	(Loss) Gain on derivative instruments	$	(160,690)	$	(510,596)	$	202,661
Commodity collars	(Loss) Gain on derivative instruments	(159,721)		(15,254)		—