We use the asset and liability method to reflect income taxes on our financial statements pursuant to ASC 740. We recognize deferred tax assets and liabilities by applying enacted tax rates to the differences between the carrying value of existing assets and liabilities and their respective tax basis and to loss carryforwards. Tax credit carryforwards are recorded as deferred tax assets. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that the change occurs. We assess the validity of deferred tax assets and loss and tax credit carryforwards and provide valuation allowances when we determine it is more likely than not that such assets, losses, or credits will not be realized. We have not recognized deferred taxes relative to foreign subsidiaries’ earnings that are deemed to be permanently reinvested. Any related taxes associated with such earnings are not material.

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

(in millions)	2019			2018
Depreciation	$	99.5		$	109.0
Right of use - leases		93.7			—
Deferred revenue		6.3			9.3
Intangibles		3.4			6.0
State taxes		19.6			19.9
Other		16.0			15.2
Deferred tax liabilities		238.5			159.4
Claims and insurance		(89.9	)		(84.8	)
Net operating loss carryforwards		(210.7	)		(199.9	)
Employee benefit accruals		(94.8	)		(88.9	)
Sale/leaseback transactions		(55.5	)		(54.5	)
Lease liabilities		(93.8	)		—
Other		(28.4	)		(20.6	)
Deferred tax assets		(573.1	)		(448.7	)
Valuation allowance		334.0			291.1
Net deferred tax assets		(239.1	)		(157.6	)
Net deferred tax (asset) liability	$	(0.6	)	$	1.8

The net deferred tax (asset) liability of ($0.6) million and $1.8 million as of December 31, 2019 and 2018, respectively, is included as a separate line item in each of the accompanying balance sheets. Current income tax payable was $1.6 million and $5.8 million as of December 31, 2019 and 2018, respectively, and is included in “Other current and accrued liabilities” in the accompanying balance sheets.

As of December 31, 2019, the Company has remaining federal net operating loss carryforwards of approximately $756.5 million. Deemed ownership changes that occurred in July 2011, in July 2013 and in January 2014 imposed annual and cumulative limits under the 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 $690.0 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, 2019, the Company has general business and other credit carryforwards of approximately $0.1 million. These credit carryforwards will likely not be utilized and will expire between 2027 and 2031 if not used.

As of December 31, 2019 and 2018, a valuation allowance of $334.0 million and $291.1 million 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:

	2019			2018			2017
Federal statutory rate		21.0	%		21.0	%		35.0	%
State income taxes, net		(0.7	%)		14.1	%		(2.8	)%
Foreign tax rate differential		(2.6	%)		12.1	%		(10.0	)%
Permanent differences		(0.6	%)		8.3	%		(8.9	)%
Valuation allowance		(17.7	)%		(17.5	)%		(48.6	)%
Benefit from intraperiod tax allocation under ASC 740		—	%		—	%		73.5	%
Net change in unrecognized tax benefits		0.6	%		(0.9	)%		0.5	%
Other, net (primarily prior year return to provision)		4.0	%		(1.6	)%		1.6	%
Effective tax rate		4.0	%		35.5	%		40.3	%

(in millions)	2019			2018			2017
Current:
Federal	$	—		$	—		$	(0.9	)
State		(3.3	)		5.4			0.8
Foreign		2.0			6.8			6.0
Current income tax expense (benefit)		(1.3	)		12.2			5.9

Deferred:
Federal		—			—			(13.3	)
State		—			—			—
Foreign		(3.0	)		(1.1	)		0.1
Deferred income tax benefit		(3.0	)		(1.1	)		(13.2	)

Income tax expense (benefit)		(4.3	)		11.1			(7.3	)

Based on the income (loss) before income taxes:
Domestic		(104.7	)		13.6			(30.5	)
Foreign		(3.6	)		17.7			12.4
Income (Loss) before income taxes	$	(108.3	)	$	31.3		$	(18.1	)

The Company applies the intraperiod tax allocation rules of ASC 740 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 2017, the Company recognized $13.3 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. There was no domestic deferred benefit recognized in 2019 or 2018, as the exception did not apply. This allocation has no effect on total tax provision or total valuation allowance.

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

(in millions)	2019			2018
Unrecognized tax benefits at January 1	$	59.2		$	56.8

Increases related to:
Tax positions taken during a prior period		—			7.1
Tax positions taken during the current period		0.5			0.4

Decreases related to:
Tax positions taken during a prior period		(0.1	)		(0.1	)
Lapse of applicable statute of limitations		(1.1	)		(4.8	)
Settlements with taxing authorities		—			(0.2	)

Unrecognized tax benefits at December 31	$	58.5		$	59.2

At December 31, 2019 and 2018, there are $9.8 million and $10.5 million of benefits that, if recognized, would affect the effective tax rate. We accrued interest of $0.9 million and $0.8 million for each of the years ended December 31, 2019 and 2018, respectively, and reversed $1.0 million and $0.3 million of previously accrued interest on uncertain tax positions during the years ended December 31, 2019 and 2018 for a net decrease of ($0.1) million for 2019 and a net increase $0.5 million for 2018, respectively. The reversals related primarily to statute expirations and other favorable resolution of prior uncertain positions. The total amount of interest accrued for uncertain tax positions is $2.7 million and $2.8 million as of December 31, 2019 and 2018. During the year ended December 31, 2019, we paid no amounts to settle audits. During the year ended December 31, 2018, 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. We have not accrued any penalties relative to uncertain tax positions. We have 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 $7.3 million as a result 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, 2019: