Assets and Liabilities Measured at Fair Value (Tables)

6 Months Ended

Jun. 30, 2026

Schedule of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following tables present the Company's financial assets and liabilities measured at fair value on a recurring basis, as of June 30, 2026 and December 31, 2025:


	June 30, 2026
(Millions of dollars)	Level 1		Level 2		Level 3		Fair Value
Financial assets







Prepaid expenses and other current assets:
Fuel derivative	$	—	$	—	$	0.8	$	0.8



Other assets
Deferred compensation plan assets	29.8		—		—		29.8

Financial liabilities



Deferred credits and other liabilities
Deferred compensation plan liabilities	(30.9)		—		—		(30.9)
	$	(1.1)	$	—	$	0.8	$	(0.3)


	December 31, 2025
(Millions of dollars)	Level 1		Level 2		Level 3		Fair Value
Financial assets







Prepaid expenses and other current assets:
Fuel derivative	$	—	$	—	$	—	$	—



Other assets
Deferred compensation plan assets	18.6		—		—		18.6

Financial liabilities



Deferred credits and other liabilities
Deferred compensation plan liabilities	(26.7)		—		—		(26.7)
	$	(8.1)	$	—	$	—	$	(8.1)

Schedule of Carrying Amounts and Estimated Fair Value of Financial Instruments

The following table presents the carrying amounts and estimated fair values of financial instruments held by the Company at June 30, 2026 and December 31, 2025.


	At June 30, 2026				At December 31, 2025

(Millions of dollars)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Financial liabilities
Current and long-term debt, excluding finance leases	$	(2,073.9)	$	(2,088.8)	$	(2,064.1)	$	(2,081.2)