Provisions for income taxes have been calculated in accordance with the provisions of ASC 740. Income from continuing operations before income taxes and a summary of the components of income tax expense in the Consolidated Statements of Income are shown below:

YEARS ENDED DECEMBER 31	2018			2017		2016
(in millions)
Income from continuing operations before income taxes	$	282.5		$	292.9	$	66.0
Income tax expense:
Current	$	46.2		$	3.1	$	26.2
Deferred		(2.7	)		73.7		(27.2	)
Total income tax expense (benefit)	$	43.5		$	76.8	$	(1.0	)

The income tax expense attributable to the consolidated results of continuing operations is different from the amount determined by multiplying income from continuing operations before income taxes by the U.S. statutory federal income tax rate of 21% in 2018 and 35% in both 2017 and 2016. The sources of the difference and the tax effects of each were as follows:

YEARS ENDED DECEMBER 31	2018			2017			2016
(in millions)
Expected income tax expense	$	59.3		$	102.5		$	23.1
Effect of the enactment of the Tax Cuts and Jobs Act		(4.3	)		(3.9	)		—
Tax difference related to investment disposals and maturities		(9.2	)		(12.7	)		(20.7	)
Stock-based compensation windfall benefit		(2.3	)		(5.3	)		—
Nondeductible expenses		1.6			1.0			1.0
Dividend received deduction		(1.2	)		(3.2	)		(3.3	)
Tax-exempt interest		(0.4	)		(0.9	)		(1.1	)
Change in liability for uncertain tax positions		—			(0.5	)		—
Other, net		—			(0.2	)		—
Income tax expense	$	43.5		$	76.8		$	(1.0	)
Effective tax rate		15.4	%		26.2	%		-1.5	%

The following are the components of the Company’s deferred tax assets and liabilities, (excluding those associated with its discontinued operations.)

DECEMBER 31	2018		2017
(in millions)
Deferred tax assets:
Loss, LAE and unearned premium reserves, net	$	129.8	$	115.7
Employee benefit plans		14.5		18.7
Tax credit carryforwards		—		23.1
Investments, net		4.1		—
Other		16.3		11.5
		164.7		169.0
Less: Valuation allowance		0.2		0.2
		164.5		168.8
Deferred tax liabilities:
Deferred acquisition costs		95.0		90.2
Investments, net		—		41.8
Software capitalization		18.3		18.0
Other		0.6		1.8
		113.9		151.8
Net deferred tax asset	$	50.6	$	17.0

Deferred tax assets are reduced by a valuation allowance if it is more likely than not that all or some portion of the deferred tax assets will not be realized. The Company believes it is more likely than not that the deferred tax assets will be realized.

In prior years, the Company completed several transactions which resulted in, for tax purposes only, realized gains in its investment portfolio. As a result of these transactions, the Company was able to utilize capital losses carried forward and to release the valuation allowance recorded against the deferred tax asset related to these losses. The releases of valuation allowances were recorded as a benefit in accumulated other comprehensive income. Previously unrealized benefits of $9.2 million, $12.7 million and $20.7 million, are recognized as part of income from continuing operations during 2018, 2017 and 2016, respectively. The remaining amount of $35.6 million in accumulated other comprehensive income will be released into income from continuing operations in future years, as the investment securities subject to these transactions are sold or mature.

The table below provides a reconciliation of the beginning and ending liability for uncertain tax positions as follows:

YEARS ENDED DECEMBER 31	2018		2017			2016
(in millions)
Liability at beginning of year, net	$	3.0	$	2.7		$	3.0
Additions for tax positions of current year		—		0.9			0.4
Subtractions as a result of a lapse of the applicable statute of limitations		—		(0.6	)		(0.7	)
Liability at end of year, net	$	3.0	$	3.0		$	2.7

There are no tax positions at December 31, 2018, 2017 and 2016 for which the ultimate deductibility is highly certain, but for which there is uncertainty about the timing of such deductibility. Because of the impact of deferred tax accounting, other than interest and penalties, a change in the timing of deductions would not impact the annual effective tax rate.

The Company recognizes interest and penalties related to unrecognized tax benefits in federal income tax expense. For the years ended December 31, 2018, 2017 and 2016 the Company recognized a de minimis amount of net interest and has not recognized any penalties associated with unrecognized tax benefits.

In 2019, the Company is expecting to release $1.7 million of liability due to the expiration of a statute of limitations.

The Company or its subsidiaries file income tax returns in the U.S. federal jurisdiction and various state jurisdictions, as well as foreign jurisdictions. The Company and its subsidiaries are subject to U.S. federal and state income tax examinations and foreign examinations for years after 2014.

On December 22, 2017, the Tax Cuts and Jobs Act (“TCJA”, “U.S. Tax Reform”, or “the Act”) was enacted in the U.S. The Act substantially changed many aspects of the U.S. Tax code, including a reduction in the U.S. corporate income tax rate from 35% to 21%. While the new corporate rate is effective on January 1, 2018, the Company has recognized the impact of the rate change on its deferred tax balances as of the enactment date. The effect of this re-measurement of the Company’s deferred tax balances was a provision of $9.4 million for the year ended December 31, 2017. This provision was recorded as a component of income tax expense in continuing operations and as a component of the Chaucer business and reflected a tax benefit of $4.1 million and an expense of $13.5 million, respectively. This amount included the revaluation of deferred taxes initially recorded through other comprehensive income and recorded through discontinued operations, such as unrealized appreciation on investments, employee benefit plan-related items, foreign currency translation adjustments and reserve adjustments for discontinued business. Deferred taxes related to the revaluation of the Company’s pension plans at December 31, 2017, as well as changes in unrealized gains and losses occurring after the Act’s enactment date, were recorded at 21% in other comprehensive income.

The Act also created a territorial tax system, which will generally allow companies to repatriate future non-U.S. sourced earnings without incurring additional U.S. taxes, by providing a 100% exemption on dividends received from certain non-U.S. subsidiaries. Although most of the Company’s non-U.S. income had been previously subject to U.S. taxes, a portion of its non-U.S. income had been indefinitely reinvested overseas and was not subject to U.S. tax until repatriated. These non-U.S. earnings were subject to a one-time mandatory toll charge totaling $12.7 million, which was recorded as a component of income tax expense in discontinued Chaucer business for the year ended December 31, 2017.

In addition, the Act limited various existing deductions such as executive compensation and introduced new income taxes on certain low-taxed non-U.S. income. Under the Act, the exemption from the $1 million limitation on certain executive compensation has been eliminated. As a result, the Company recognized a provision of $0.2 million for the year ended December 31, 2017.

The Act modified the provisions applicable to the determination of the tax basis of unpaid loss reserves. These modifications impact the payment pattern and applicable interest rate. The Act instructed the Treasury Department to provide discount factors and other guidance necessary to determine the appropriate transition adjustment. This information was released in November 2018 and the transition adjustment has been determined to total $126.2 million, resulting in a deferred tax liability of $26.5 million. This transitional amount will be taken into account ratably over eight years beginning in calendar year 2018. These provisions have no overall effect on the net deferred tax asset or income tax expense for the years ended December 31, 2017 and 2018.

The cumulative effect of the enactment of TCJA was an expense of $22.3 million for the year ended December 31, 2017, comprising the aforementioned three components. The Company’s estimates were not based upon provisional amounts, as defined in the SEC’s Staff Accounting Bulletin No. 118.