Other Income (Expense), Net

12 Months Ended

Dec. 31, 2023

Other Income and Expenses [Abstract]

Other Income (Expense), Net

13. 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.

Supply Chain Financing. During the years ended December 31, 2023 and December 31, 2022, we sold trade accounts receivable totaling $1,240.6 million and $1,589.3 million, respectively, related to these supply chain financing arrangements, of which our customers’

financial institutions applied discount fees totaling $29.7 million and $23.3 million, respectively. To the extent discount fees related to the sale of trade accounts receivable under supply chain financing arrangements are not reimbursed by our customers, they are included in Other income (expense), net. As of December 31, 2023, we had been and/or expected to be substantially reimbursed by our customers for these discount fees, in accordance with the underlying sales agreements.