Income Taxes (Tables)

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Components of Income from Continuing Operations Before Income Taxes and Summary of Components of Income Tax Expense (Benefit)

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	2023			2022			2021
(in millions)
Income from continuing operations before income taxes	$	41.1		$	144.0		$	521.3
Income tax expense (benefit):
Current	$	32.6		$	73.7		$	77.5
Deferred		(25.0	)		(46.5	)		23.8
Total income tax expense	$	7.6		$	27.2		$	101.3

Schedule of Effective Income Tax Rate Reconciliation

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%. The sources of the difference and the tax effects of each were as follows:

YEARS ENDED DECEMBER 31	2023			2022			2021
(in millions)
Expected income tax expense	$	8.7		$	30.3		$	109.5
Nondeductible expenses		3.8			3.1			2.3
Tax difference related to investment disposals and maturities		(1.3	)		(1.4	)		(4.6	)
Stock-based compensation windfall benefit		(1.1	)		(3.2	)		(2.6	)
Change in uncertain tax positions		(0.9	)		—			—
Current year federal tax credits		(0.7	)		(0.4	)		(0.5	)
Dividend received deduction		(0.5	)		(1.0	)		(1.2	)
Prior years’ federal research tax credits		—			—			(1.7	)
Other, net		(0.4	)		(0.2	)		0.1
Income tax expense	$	7.6		$	27.2		$	101.3
Effective tax rate		18.5	%		18.9	%		19.4	%

Schedule of Deferred Tax Assets and Liabilities

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

DECEMBER 31	2023		2022
(in millions)
Deferred tax assets:
Loss, LAE and unearned premium reserves, net	$	197.6	$	185.6
Investments, net		97.2		144.3
Employee benefit plans		7.3		8.4
Other		9.2		7.3
Total deferred tax assets		311.3		345.6
Deferred tax liabilities:
Deferred acquisition costs		130.4		127.0
Software capitalization		7.6		19.4
Total deferred tax liabilities		138.0		146.4
Net deferred tax asset	$	173.3	$	199.2

Summary of Income Tax Uncertainties

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

YEARS ENDED DECEMBER 31	2023			2022		2021
(in millions)
Liability at beginning of year, net	$	2.2		$	2.0	$	0.9
Additions for tax positions of current year		—			0.2		2.0
Subtractions as a result of a lapse of the applicable statute of limitations		(0.9	)		—		(0.9	)
Liability at end of year, net	$	1.3		$	2.2	$	2.0