Debt and Credit Facility

12 Months Ended

Dec. 31, 2023

Debt Disclosure [Abstract]

Debt and Credit Facility

9. Debt and Credit Facility

Senior Notes

At December 31, 2023 and 2022, we had outstanding fixed-rate unsecured Senior Notes with varying maturity dates. The stated interest rates and aggregate principal amounts of such Senior Notes were, respectively: (i) 4.50% and $550.0 million (“4.50% Senior Notes”) and (ii) 4.625% and $500.0 million (“4.625% Senior Notes”). Our Senior Notes do not require us to make any mandatory redemptions or sinking fund payments. The following table summarizes key details of our outstanding Senior Notes:

				Outstanding (in millions of dollars)
	Issuance Date	Maturity	Effective Interest Rate	As of December 31, 2023			As of December 31, 2022
4.50% Senior Notes	May 2021	June 2031	4.7%	$	550.0		$	550.0
4.625% Senior Notes	November 2019	March 2028	4.8%		500.0			500.0
Total debt					1,050.0			1,050.0
Unamortized issuance costs					(10.2	)		(11.9	)
Total carrying amount				$	1,039.8		$	1,038.1

The following table presents the fair value of our outstanding Senior Notes, which are Level 1 liabilities (in millions of dollars):

	As of December 31,
	2023		2022
4.50% Senior Notes	$	474.1	$	438.7
4.625% Senior Notes	$	462.4	$	440.4

Revolving Credit Facility

In October 2019, we entered into a Revolving Credit Facility. Joining us as borrowers under the Revolving Credit Facility are four of our wholly owned domestic operating subsidiaries: (i) Kaiser Aluminum Investments Company; (ii) Kaiser Aluminum Fabricated Products, LLC; (iii) Kaiser Aluminum Washington, LLC; and (iv) Kaiser Aluminum Warrick, LLC.

In April 2022, we entered into Amendment No. 3 to our Revolving Credit Facility. As amended, the Revolving Credit Facility, among other things: (i) increased the commitment from $375.0 million to $575.0 million (of which up to a maximum of $50.0 million may be utilized for letters of credit); (ii) extended the maturity date from the earlier of (a) February 2024 (if certain conditions were met) and (b) October 2024 to April 2027; (iii) removed eligible equipment from the borrowing base and as collateral; and (iv) updated relevant benchmark provisions from LIBOR to Term SOFR. Our effective interest rate on outstanding borrowings under the amended Revolving Credit Facility is based on the rates of Base Rate Loans and SOFR Loans (as defined in the amended Revolving Credit Facility). For borrowings outstanding during the year ended December 31, 2023, the rate for Base Rate Loans was equal to the prevailing Prime Rate plus 0.25%, while the rate for SOFR Loans, which are made for one or three month periods, was equal to the Term SOFR Reference Rate (as defined in the amended Revolving Credit Facility) plus 1.35%. Outstanding borrowings under the Revolving Credit Facility are reported within Long-term debt, net, on our Consolidated Balance Sheets. We had no outstanding borrowings as of December 31, 2023 under our Revolving Credit Facility, after repaying borrowings of $215.1 million incurred during the year ended December 31, 2023. In addition, we had no borrowings under the Revolving Credit Facility during the year ended December 31, 2022.

The following table summarizes availability and usage of our Revolving Credit Facility as determined by a borrowing base calculated as of December 31, 2023 (in millions of dollars):

Revolving Credit Facility borrowing commitment	$	575.0
Borrowing base availability	$	543.5
Less: Outstanding borrowings under Revolving Credit Facility		—
Less: Outstanding letters of credit under Revolving Credit Facility		(26.8	)
Remaining borrowing availability	$	516.7

Interest Expense and Future Maturities

The following table presents interest expense relating to our Senior Notes and Revolving Credit Facility (in millions of dollars):

	Year Ended December 31,
	2023			2022			2021
Senior Notes interest expense, including debt issuance cost amortization	$	49.6		$	49.6		$	49.0
Revolving Credit Facility interest expense, including commitment fees and finance cost amortization		3.0			2.0			1.4
Interest expense on finance lease liabilities		0.7			0.3			0.3
Interest expense capitalized as construction in progress		(6.4	)		(3.6	)		(1.2	)
Total interest expense	$	46.9		$	48.3		$	49.5

The following table presents the future principal payments for our Senior Notes and Revolving Credit Facility as of December 31, 2023 (in millions of dollars):

Year ending December 31,
2024	$	—
2025		—
2026		—
2027		—
2028		500.0
Thereafter		550.0
Total	$	1,050.0