Income Taxes: On December 22, 2017, the Tax Act was signed into law and included numerous changes to existing tax law, including a reduction in the federal corporate income tax rate from 35 percent to 21 percent. The rate reduction and other changes took effect on January 1, 2018. Other changes such as remeasurement of deferred tax assets and liabilities were effective as of the fourth quarter of 2017.

In connection with the Company’s analysis of the impact of the Tax Act, the Company recorded a net tax benefit of $154.0 million related to the remeasurement and other discrete adjustments to the Company’s deferred tax assets and liabilities during the year ended December 31, 2017. In addition, the Company recorded a non-cash tax adjustment of

$2.9 million that increased current income taxes during the year ended December 31, 2018. This adjustment related to the application of an estimated 6.2 percent sequestration on alternative minimum tax (AMT) refunds for the years 2018 to 2021. On January 19, 2019, the Internal Revenue Service issued new guidance indicating that sequestration would not apply to refundable AMT credits. In accordance with this new guidance, the Company recorded a non-cash tax adjustment of $2.9 million that reduced current income taxes during the year ended December 31, 2019.

Income taxes for the years ended December 31, 2019, 2018 and 2017 consisted of the following:

(1)	Current income taxes for the years ended December 31, 2019 and 2018 include a non-cash income tax benefit of $2.9 million and a non-cash income tax expense of $2.9 million, respectively, which relates to discrete adjustments as a result of applying the provisions of the Tax Act.

(2)	Deferred income taxes for the year ended December 31, 2017 includes a non-cash income tax benefit of $154.0 million, which relates to the remeasurement of the Company’s deferred tax assets and liabilities and other discrete adjustments as a result of applying the provisions of the Tax Act.

Income taxes for the years ended December 31, 2019, 2018 and 2017 differ from amounts computed by applying the statutory federal rate to income before income taxes for the following reasons:


	Years Ended December 31,
	2019		2018		2017
Computed federal income tax expense	21.0	%	21.0	%	35.0	%
State income tax	4.1	%	3.4	%	2.6	%
Valuation allowance	(0.3)	%	(0.7)	%	1.4	%
Foreign taxes	1.2	%	0.6	%	0.1	%
Remeasurement and discrete adjustments related to the Tax Act (1)	(2.7)	%	2.0	%	(123.0)	%
Share-based payments	(0.1)	%	0.1	%	(1.4)	%
Other — net	0.1	%	(0.2)	%	0.8	%
Effective income tax rate	23.3	%	26.2	%	(84.5)	%

(1)

Effective income tax rate for the years ended December 31, 2019, 2018 and 2017 includes the impact of a non-cash income tax benefit of $2.9 million, or 2.7 percent, a non-cash income tax expense of $2.9 million, or 2.0 percent, and a non-cash income tax benefit of $154.0 million, or 123.0 percent, respectively, related to the remeasurement of the Company’s deferred assets and liabilities and other discrete adjustments as a result of applying the provisions of the Tax Act.

The tax effects of temporary differences that gave rise to significant portions of the deferred tax assets and deferred tax liabilities at December 31, 2019 and 2018, were as follows:


	As of December 31,
(In millions)	2019		2018
Deferred tax assets:
Operating lease liabilities	$	63.1	$	—
Pension and post-retirement plans		19.2		20.2
Multi-employer withdrawal liabilities		16.1		16.6
Federal net operating losses		14.3		15.2
State net operating losses		7.3		7.4
U.S. State alternative minimum tax credits		6.7		5.9
Insurance reserves		5.9		5.6
Deferred compensation		5.8		7.0
Foreign losses		3.9		5.1
Other		2.0		4.7
Total deferred tax assets		144.3		87.7
Valuation allowance		(10.6)		(11.5)
Total deferred tax assets, net of valuation allowance		133.7		76.2

Deferred tax liabilities:
Basis differences for property and equipment		319.2		302.1
Operating lease right of use assets		61.1		—
Intangibles		39.7		38.4
Lease financing		23.7		26.0
Capital Construction Fund		12.5		7.0
Investment in SSAT		7.4		11.4
Other		7.7		4.0
Total deferred tax liabilities		471.3		388.9
Deferred tax liability, net	$	337.6	$	312.7

Valuation Allowance: Valuation allowances recorded against the Company’s foreign income tax net operating losses (“NOLs”) and a portion of the state income tax NOLs were $10.6 million and $11.5 million as of December 31, 2019 and 2018, respectively. The Company believes that it is more likely than not that the benefit from these amounts will not be realized. The Company recorded a decrease (increase) to its valuation allowance of $0.9 million, ($1.1) million and $1.7 million during the years ended December 31, 2019, 2018 and 2017, respectively.

Net Operating Losses and Tax Credit Carryforwards: The Company’s NOLs and tax credit carryforwards at December 31, 2019 and 2018 were as follows:


(In millions)	Expiration Date	2019		2018
U.S. Federal income tax NOLs	Various dates beginning in 2027	$	71.2	$	74.5
U.S. State income tax NOLs (1)	Various dates beginning in 2032	$	184.5	$	189.2
U.S. State alternative minimum tax credit	No expiration date	$	6.7	$	5.9
Foreign income tax NOLs (2)	No expiration date	$	14.0	$	18.4

(1)	The Company does not expect to benefit from $157.9 million and $152.0 million of U.S. State income tax NOLs as of December 31, 2019 and 2018, respectively.

(2)	The Company has recorded a valuation allowance of $14.0 million and $18.4 million against the foreign income tax NOLs as of December 31, 2019 and 2018, respectively.

The U.S. federal and state income tax NOLs in the Company’s filed income tax returns include unrecognized tax benefits. The deferred tax assets recognized for those NOLs are presented net of these unrecognized tax benefits. As a result of changes in tax legislation, the use of a portion of the Company’s domestic NOL and tax credit carryforwards may be limited in future periods. Further, a portion of the federal and state income tax NOLs and tax credit carryforwards may expire before being applied to reduce future income tax liabilities.

Unrecognized Tax Benefits: Total unrecognized benefits represent the amount that, if recognized, would favorably affect the Company’s incomes taxes and effective tax rate in future periods. The Company does not expect a material change in gross unrecognized benefits in the next twelve months. A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows:


Unrecognized Tax Benefits (in millions)	Amount
Balance at December 31, 2016	$	20.4
Changes in tax positions of prior years, net		1.1
Reductions for lapse of statute of limitations		(0.1)
Revaluation of unrecognized tax benefits due to the Tax Act (1)		(5.5)
Balance at December 31, 2017		15.9
Changes in tax positions of prior years, net		(0.3)
Reductions for lapse of statute of limitations		(0.5)
Balance at December 31, 2018		15.1
Changes in tax positions of prior years, net		2.1
Reductions for lapse of statute of limitations		(0.8)
Balance at December 31, 2019	$	16.4

(1)	Amount relates to the impact of applying the Tax Act during the year ended December 31, 2017.

Included in the balance of unrecognized tax benefits at December 31, 2019 are potential benefits of $13.5 million that, if recognized, would affect the Company’s income taxes and effective tax rate. The Company recognizes potential accrued interest and penalties related to unrecognized tax benefits in income taxes. To the extent interest and penalties are not ultimately assessed with respect to the settlement of uncertain tax positions, amounts accrued will be reduced and reflected as a reduction of the Company’s income taxes. Interest accrued related to the balance of unrecognized tax benefits totaled $0.1 million and $0.4 million as of December 31, 2019 and 2018, respectively.

The Company is no longer subject to U.S. federal income tax audits for years before 2014. The Company is routinely involved in state, local income and excise tax audits, and foreign tax audits.