Long-term Debt (Tables)

3 Months Ended

Mar. 31, 2023

Debt Disclosure [Abstract]

Schedule of Long-term Debt Instruments

The Company’s total indebtedness as of March 31, 2023 and December 31, 2022 consisted of the following:

Debt Instrument (defined below, as applicable)	March 31, 2023		December 31, 2022
	(Dollars in millions)
3.250% Convertible Senior Notes due March 2028 (2028 Convertible Notes)	$	320.0	$	320.0
Finance lease obligations	25.0		23.6
Less: Debt issuance costs	(9.4)		(9.8)
	335.6		333.8
Less: Current portion of long-term debt	13.2		13.2
Long-term debt	$	322.4	$	320.6

Schedule of Interest Charges

Additionally, the table sets forth the amount of cash paid for interest and the amount of non-cash interest expense primarily related to the amortization of debt issuance costs.

	Three Months Ended March 31,
	2023		2022
	(Dollars in millions)
Indebtedness	$	6.4	$	25.9
Financial assurance instruments	12.0		13.5
Interest expense	$	18.4	$	39.4
Cash paid for interest	$	19.1	$	37.2
Non-cash interest expense	$	1.6	$	3.8