Income Tax Matters (Tables)

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Income (Loss) Before Income Taxes by Geographic Area

The following table presents Income (loss) before income taxes by geographic area (in millions of dollars):

	Year Ended December 31,
	2023		2022			2021
Domestic	$	48.0	$	(44.6	)	$	(30.2	)
Foreign		8.3		6.7			6.2
Income (loss) before income taxes	$	56.3	$	(37.9	)	$	(24.0	)

Income Tax (Provision) Benefit

The following table presents the components of Income tax (provision) benefit (in millions of dollars):

	Federal			Foreign			State			Total
Year Ended December 31, 2023
Current	$	—		$	(2.2	)	$	0.6		$	(1.6	)
Deferred		(11.6	)		0.1			1.0			(10.5	)
Benefit applied to decrease AOCI		2.5			0.1			0.4			3.0
Income tax (provision) benefit	$	(9.1	)	$	(2.0	)	$	2.0		$	(9.1	)
Year Ended December 31, 2022
Current	$	—		$	(1.1	)	$	(2.5	)	$	(3.6	)
Deferred		8.9			(0.8	)		1.6			9.7
Benefit applied to decrease AOCI		1.7			0.2			0.3			2.2
Income tax benefit (provision)	$	10.6		$	(1.7	)	$	(0.6	)	$	8.3
Year Ended December 31, 2021
Current	$	—		$	(2.4	)	$	(3.5	)	$	(5.9	)
Deferred		2.1			0.5			4.2			6.8
Benefit applied to decrease AOCI		3.7			0.3			0.6			4.6
Income tax benefit (provision)	$	5.8		$	(1.6	)	$	1.3		$	5.5

Reconciliation of Income Tax (Provision) Benefit based on Effective Income Tax Rate and Statutory Tax Rate

The following table presents a reconciliation between the (provision) benefit for income taxes and the amount computed by applying the federal statutory income tax rate to Income (loss) before income taxes (in millions of dollars):

	Year Ended December 31,
	2023			2022			2021
Amount of federal income tax (provision) benefit based on the statutory rate	$	(11.8	)	$	8.0		$	5.0
Decrease in federal valuation allowances		—			1.1			0.2
Non-deductible compensation expense		(1.6	)		(0.9	)		(0.5	)
Non-deductible benefit (expense)		0.2			(1.0	)		(0.2	)
State income tax benefit (provision), net of federal benefit1		1.5			(0.5	)		1.0
Research and development credit		3.2			2.2			0.6
Foreign income tax expense		(0.3	)		(0.3	)		(0.3	)
Foreign undistributed earnings		(0.3	)		(0.3	)		(0.3	)
Income tax (provision) benefit	$	(9.1	)	$	8.3		$	5.5

1.The state income tax expense was $1.4 million in 2023, reflecting a decrease of $1.9 million due to state net operating loss (“NOL”) carryforward expirations and tax rate true-ups in various states and a $1.0 million decrease in the valuation allowance relating to certain state net operating losses. The state income tax benefit was $1.1 million in 2022, reflecting an increase of $1.5 million due to

state NOL carryforward expirations and tax rate true-ups in various states and a $0.1 million increase in the valuation allowance relating to certain state net operating losses. The state income tax benefit was $0.7 million in 2021, reflecting an increase of $1.3 million due to state NOL carryforward expirations and tax rate true-ups in various states, offset by a $1.6 million decrease in the valuation allowance relating to certain state net operating losses.

Deferred Tax Assets and Liabilities

The following table presents the components of our net deferred income tax assets and liabilities (in millions of dollars):

	As of December 31,
	2023			2022
Deferred income tax assets:
Loss and credit carryforwards	$	39.6		$	47.7
Defined benefit plans		3.6			2.9
Other assets		36.8			36.3
Lease assets		8.7			10.6
Inventories		29.5			46.9
Excess interest carryforward		14.0			12.2
Research & development capitalization		16.9			8.7
Valuation allowances		(2.7	)		(3.7	)
Total deferred income tax assets		146.4			161.6
Deferred income tax liabilities:
Property, plant and equipment		(142.6	)		(147.0	)
Lease liabilities		(8.7	)		(9.3	)
Undistributed foreign earnings		(3.0	)		(2.7	)
Total deferred income tax liabilities		(154.3	)		(159.0	)
Net deferred income tax (liabilities) assets	$	(7.9	)	$	2.6

Reconciliation of Changes in Gross Unrecognized Tax Benefits

We have gross unrecognized benefits relating to uncertain tax positions. The following table presents a reconciliation of changes in the gross unrecognized tax benefits (in millions of dollars):

	Year Ended December 31,
	2023		2022			2021
Gross unrecognized tax benefits at beginning of period	$	5.0	$	4.1		$	3.8
Gross increases for tax positions of current year		1.3		0.9			0.3
Gross increases for tax positions of prior years		0.2		0.1			0.4
Gross decreases for tax positions of prior years		—		(0.1	)		(0.3	)
Settlements		—		—			(0.1	)
Gross unrecognized tax benefits at end of period	$	6.5	$	5.0		$	4.1