Income Taxes (Tables)

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

Components of pre-tax book income (loss)

The components of pre-tax book income (loss) consist of the following:
	Year Ended December 31,
	2022		2021		2020
U.S.	$	(193.6)	$	(250.5)	$	(76.7)
Foreign	227.0		52.9		(49.6)
Total	$	33.4	$	(197.6)	$	(126.3)

Significant components of the income before income tax expense

Significant components of income tax expense consist of the following:
	Year Ended December 31,
	2022		2021		2020
Current:
U.S. federal current expense (benefit)	$	—	$	—	$	—
State current expense (benefit)	0.2		—		—
Foreign current expense (benefit)	4.0		0.1		4.0
Total current expense (benefit)	4.2		0.1		4.0
Deferred:
U.S. federal deferred (benefit)	(0.3)		(0.2)		(1.2)
State deferred benefit	—		—		—
Foreign deferred tax expense (benefit)	43.5		(30.5)		(5.9)
Total deferred expense (benefit)	43.2		(30.7)		(7.1)
Total income tax expense (benefit)	$	47.4	$	(30.6)	$	(3.1)

Reconciliation of the statutory U.S. Federal income tax rate to the effective income tax rate on income (loss)

A reconciliation of the statutory U.S. Federal income tax rate to the effective income tax rate on income (loss) is as follows:
	2022		2021		2020
Federal Statutory Rate	21.0	%	21.0	%	21.0	%
Permanent differences	(15.2)		(0.3)		(1.2)
State taxes, net of Federal benefit	0.1		—		—
Rate change	0.4		2.5		(0.2)
Foreign earnings taxed at different rates than U.S.	(0.8)		(3.9)		(0.3)
Valuation allowance	(4.2)		(15.9)		(4.3)
Helguvik investment	—		26.4		—
Foreign restructuring	—		—		(2.3)
Foreign dividends and inclusions	122.9		(10.1)		(1.5)
Net operating loss expiration and remeasurement	43.1		(5.2)		(10.8)
Provision to return	(19.1)		(0.1)		(0.4)
Changes in uncertain tax reserves	(5.3)		1.3		1.4
Other	(0.9)		(0.2)		1.0
Effective tax rate	142.0	%	15.5	%	2.4	%

Significant components of deferred tax assets and liabilities

The significant components of our deferred tax assets and liabilities as of December 31 are as follows:

 

	2022		2021
Deferred tax assets:
Accrued postretirement benefit cost	$	25.7	$	29.5
Net operating losses and tax credits	395.8		453.1
Disallowed interest expense	27.7		17.8
Derivative and hedging contracts	—		18.6
Fixed asset tax over book basis	17.0		—
Other	26.1		20.7
Total deferred tax assets	492.3		539.7
Valuation allowance	(487.9)		(485.8)
Net deferred tax assets	$	4.4	$	53.9
Deferred tax liabilities:
Fixed asset book over tax basis	(60.5)		(86.2)
Derivatives	(19.0)		—
Foreign basis differences	(19.8)		(19.6)
Other	(7.9)		(6.8)
Total deferred tax liabilities	(107.2)		(112.6)
Net deferred tax liability	$	(102.8)	$	(58.7)

Changes in valuation allowance

	2022		2021		2020
Beginning balance, valuation allowance	$	485.8	$	499.4	$	492.4
Remeasurement of deferred tax assets	—		—		—
Release of valuation allowance	—		—		—
Expiration of net operating losses	(15.4)		(13.2)		(11.7)
Other change in valuation allowance	17.5		(0.4)		18.7
Ending balance, valuation allowance	$	487.9	$	485.8	$	499.4

Significant components of net operating loss carryforwards

The significant components of our NOLs are as follows:

 

	2022		2021
Federal (1)	$	1,487.8	$	1,568.4
State (2)	1,182.7		1,161.0
Foreign (3)	106.0		321.7

(1)The federal NOL begins to expire in 2028.

(2)The state NOLs begin to expire in 2027.

(3)The Icelandic NOLs expire between 2023 and 2026.

Reconciliation of beginning and ending amounts of gross unrecognized tax benefits

A reconciliation of the beginning and ending amounts of gross unrecognized tax benefits (excluding interest) is as follows:

	2022		2021		2020
Balance as of January 1,	$	4.0	$	6.5	$	8.2
Additions based on tax positions related to the current year	0.3		—		—
Decreases due to lapse of applicable statute of limitations	(2.1)		(2.5)		(1.7)
Settlements	—		—		—
Balance as of December 31,	$	2.2	$	4.0	$	6.5