Other Income (Expense), Net (Tables)

12 Months Ended

Dec. 31, 2023

Other Income and Expenses [Abstract]

Other Income (Expense), Net

The following table presents the components of Other income (expense), net, (in millions of dollars):

	Year Ended December 31,
	2023			2022			2021
Interest income	$	1.7		$	1.3		$	0.2
Net periodic postretirement benefit cost		(8.4	)		(5.6	)		(4.1	)
Unrealized gain (loss) on equity securities		0.6			(1.2	)		(0.2	)
Loss on extinguishment of debt1		—			—			(35.9	)
Gain on disposition of property, plant and equipment		13.8			6.0			0.5
Post-acquisition funding received from Alcoa Corporation2		—			6.0			—
All other, net		(0.3	)		(0.1	)		0.6
Other income (expense), net	$	7.4		$	6.4		$	(38.9	)

1.In May 2021, we redeemed in full our 6.50% Senior Notes at a redemption price of 108.83% of the $350.0 million principal amount plus $1.3 million of accrued and unpaid interest for a total net cash outflow of $382.2 million. Upon redemption of the 6.50% Senior Notes, we recorded a loss on extinguishment of debt of $35.9 million, which included the premium payment of $30.9 million and a write-off of the remaining unamortized premium and debt issuance costs of $5.0 million.

2.Reimbursement received for repairs and maintenance expenditures on certain machinery and equipment that we had purchased from Alcoa in connection with our March 31, 2021 acquisition of Warrick.