Deferred tax assets (liabilities) were comprised of the following at December 31:

(in millions)	2020			2019
Depreciation	$	(83.8	)	$	(99.5	)
Operating lease right-of-use assets		(65.3	)		(93.7	)
Deferred revenue		(3.3	)		(6.3	)
Intangibles		(2.9	)		(3.4	)
State taxes		(19.6	)		(19.6	)
Other, including debt and interest		(22.3	)		(16.0	)
Deferred tax liabilities		(197.2	)		(238.5	)
Claims and insurance		84.4			89.9
Net operating loss carryforwards		216.7			210.7
Employee benefit accruals		23.9			94.8
Sale/leaseback transactions		53.0			55.5
Operating lease liabilities		68.7			93.8
Employer payroll taxes		20.0			—
Other, including debt and interest		37.0			28.4
Deferred tax assets		503.7			573.1
Valuation allowance		(305.6	)		(334.0	)
Net deferred tax assets		198.1			239.1
Net deferred tax asset	$	0.9		$	0.6

The net deferred tax asset of $0.9 million and $0.6 million as of December 31, 2020 and 2019, respectively, is included as a separate line item of the accompanying consolidated balance sheets. Current income tax payable was $1.9 million and $1.6 million as of December 31, 2020 and 2019, respectively, and is included in “Other current and accrued liabilities” in the accompanying consolidated balance sheets.

As of December 31, 2020, the Company has remaining federal net operating loss carryforwards of approximately $753.1 million. Deemed ownership changes that occurred in January 2014 and in prior years imposed annual and cumulative limits under the Internal Revenue Code on the utilization of these carryforwards. These limits are not expected to inhibit the Company’s ability to utilize these losses over their carry forward periods. Carryforwards of $684.6 million incurred prior to 2018 expire between 2030 and 2037. Pursuant to the Tax Act, net operating losses incurred after 2017 are available to be carried forward indefinitely. As of December 31, 2020, the Company has only nominal amounts of general business and other credit carryforwards, which will likely not be utilized and will expire between 2027 and 2031 if not used.

As of December 31, 2020 and 2019, a valuation allowance of $305.6 million and $334.0 million, respectively, has been established for deferred tax assets because, based on available sources of future taxable income, it is more likely than not that those assets will not be realized.

A reconciliation between income taxes at the federal statutory rate and the consolidated effective tax rate follows for the years ended December 31:

	2020			2019			2018
Federal statutory rate		21.0	%		21.0	%		21.0	%
State income taxes, net		(1.2	%)		(0.7	%)		14.1	%
Foreign tax rate differential		(1.0	%)		(2.6	%)		12.1	%
Permanent differences		(2.3	%)		(0.6	%)		8.3	%
Valuation allowance		(19.7	)%		(17.7	)%		(17.5	)%
Benefit from intraperiod tax allocation		20.0	%		—	%		—	%
Net change in unrecognized tax benefits		8.9	%		0.6	%		(0.9	)%
Other, net (primarily prior year return to provision)		1.1	%		4.0	%		(1.6	)%
Effective tax rate		26.8	%		4.0	%		35.5	%

The income tax provision (benefit) consisted of the following for the years ended December 31:

(in millions)	2020			2019			2018
Current:
Federal	$	(6.2	)	$	—		$	—
State		0.4			(3.3	)		5.4
Foreign		1.1			2.0			6.8
Current income tax expense (benefit)		(4.7	)		(1.3	)		12.2

Deferred:
Federal		(9.4	)		—			—
State		(5.2	)		—			—
Foreign		(0.3	)		(3.0	)		(1.1	)
Deferred income tax benefit		(14.9	)		(3.0	)		(1.1	)

Income tax expense (benefit)	$	(19.6	)	$	(4.3	)	$	11.1

Based on the income (loss) before income taxes:
Domestic	$	(77.4	)	$	(104.7	)	$	13.6
Foreign		4.3			(3.6	)		17.7
Income (Loss) before income taxes	$	(73.1	)	$	(108.3	)	$	31.3

The Company applies the intraperiod tax allocation rules to allocate income taxes among continuing operations, other comprehensive income (loss), and additional paid-in capital when our situation meets the criteria as prescribed in the rule. During 2020, the Company recognized $14.6 million of deferred benefit in the statement of consolidated operations and an equal and offsetting deferred tax expense in other comprehensive income (loss) included in the statement of consolidated comprehensive income (loss) due to the application of the exception within the intraperiod tax allocation rules. This allocation has no effect on total tax provision or total valuation allowance. There was no domestic deferred benefit recognized in 2019 or 2018, as the exception did not apply.

A rollforward of the total amount of unrecognized tax benefits for the years ended December 31 is as follows:

(in millions)	2020			2019
Unrecognized tax benefits at January 1	$	58.5		$	59.2

Increases related to:
Tax positions taken during a prior period		—			—
Tax positions taken during the current period		0.3			0.5

Decreases related to:
Tax positions taken during a prior period		(0.2	)		(0.1	)
Lapse of applicable statute of limitations		(17.9	)		(1.1	)

Unrecognized tax benefits at December 31	$	40.7		$	58.5

At December 31, 2020 and 2019, there are $3.3 million and $9.8 million, respectively, of benefits that, if recognized, would affect the effective tax rate. The differences between these amounts and the amounts appearing in the table above represent unrecognized tax benefits which have been netted against deferred tax assets for net operating loss carryforwards and not recorded to the liability for unrecognized tax benefits. During the year ended December 31, 2020 we paid no amounts to settle audits. During the year ended December 31, 2019, we paid inconsequential amounts of tax and interest to settle state audits of tax years 2010 through 2014 for certain of our subsidiaries, and we reduced our previously recorded liability for unrecognized tax benefits accordingly.

During 2019, the Company experienced only nominal activities with regard to interest on the uncertain tax positions. The Company accrued no penalties relative to uncertain tax positions in either 2020 or 2019. The Company has elected to treat interest and penalties on uncertain tax positions as “Interest expense” and “Other operating expenses”, respectively.

It is reasonably possible that the existing unrecognized tax benefits may decrease over the next twelve months by as much as $0.7 million because of developments in examinations, or from the expiration of statutes of limitation.

Tax years that remain subject to examination for our major tax jurisdictions as of December 31, 2020:

During 2020, the CARES Act was enacted in response to the COVID-19 pandemic. The CARES Act contains numerous income tax provisions, such as relaxing the limitations on the deductibility of interest and the carryback of net operating losses for specific periods. The Company has performed an analysis of these provisions and due to the unavailability of excess taxable income in the current or carry back periods, and the application of a valuation allowance to deferred tax assets, the Company's effective income tax rate and its tax provision are currently unaffected by the income tax provisions of the CARES Act.