LONG-TERM DEBT (Tables)

12 Months Ended

Dec. 31, 2024

Long-Term Debt, Unclassified [Abstract]

Schedule of Long-Term Debt Instruments

The table below presents a summary of our long-term debt outstanding for the periods indicated:

		December 31,
	Interest Rate	2024		2023
		(Thousands of dollars)
Senior Notes due:
February 2024	3.610%	$	—	$	300,000
March 2024	1.100%	—		473,000
April 2029	5.100%	550,000		300,000
May 2030	2.000%	300,000		300,000
September 2032	4.250%	300,000		300,000
February 2044	4.658%	600,000		600,000
November 2048	4.500%	400,000		400,000
Total Senior Notes		2,150,000		2,673,000
KGSS-I Securitized Utility Tariff Bonds	5.486%	287,345		315,284
Unamortized discounts, net of premiums, on long-term debt		(3,624)		(7,615)
Debt issuance costs (a)		(20,691)		(21,092)
Other	8.000%	1,226		1,238
Total long-term debt, net		2,414,256		2,960,815
Less: current maturities of KGSS-I securitized utility tariff bonds, net		28,956		27,430
Less: current maturities of other long-term debt, net		14		772,984
Noncurrent portion of long-term debt, net		$	2,385,286	$	2,160,401

(a) Includes issuance costs and discounts for the KGSS-I Securitized Utility Tariff Bonds of $4.8 million and $5.3 million, at December 31, 2024 and December 31, 2023 respectively.