Financing Arrangements and Debt (Tables)

12 Months Ended

Dec. 31, 2022

Debt Disclosure [Abstract]

Schedule of Long-term Debt

Long-term debt consisted of the following as of December 31, 2022 and 2021:

	December 31,
(Thousands of dollars)	2022		2021
Notes payable
6.875% notes, due August 2024	$	—	$	242,428
5.75% notes, due August 2025	248,675		548,675
5.875% notes, due December 2027	543,249		543,249
6.375% notes, due July 2028	451,934		550,000
7.05% notes, due May 2029	250,000		250,000
6.125% notes, due December 2042 ¹	339,761		349,000
Total notes payable	1,833,619		2,483,352
Unamortized debt issuance cost and discount on notes payable	(15,324)		(22,773)
Total notes payable, net of unamortized discount	1,818,295		2,460,579
Capitalized lease obligation, due through March 2029 ¹	4,844		5,489
Total debt including current maturities	1,823,139		2,466,068
Current maturities	(687)		(654)
Total long-term debt	$	1,822,452	$	2,465,414

1 Coupon rate may fluctuate 25 basis points if rating is periodically downgraded or upgraded by S&P and Moody’s.