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Investment Income and Gains and Losses (Tables)

12 Months Ended

Dec. 31, 2025

Investments, Debt and Equity Securities [Abstract]

Components of Net Investment Income

The components of net investment income were as follows:

YEARS ENDED DECEMBER 31		2025				2024				2023
(in millions)
Fixed maturities		$	401.4			$	324.4			$	283.2
Limited partnerships			27.1				20.6				30.0
Mortgage loans			11.2				14.4				15.8
Equity securities			3.6				3.2				6.4
Short-term and other investments			26.4				25.2				10.6
Gross investment income			469.7				387.8				346.0
Less: investment expenses			(15.3	)			(15.2	)			(13.9	)
Net investment income		$	454.4			$	372.6			$	332.1

Schedule of Net Realized and Unrealized Gains (Losses) on Investments Including Impairments

Net realized and unrealized gains (losses) on investments, including impairments, were as follows:

YEARS ENDED DECEMBER 31		2025				2024				2023
(in millions)
Fixed maturities		$	(61.8	)		$	(89.6	)		$	(20.2	)
Equity securities			19.0				14.2				(5.6	)
Mortgage loans			(2.5	)			(0.5	)			(6.9	)
Other investments			(0.7	)			0.1				0.2
Net realized and unrealized investment losses		$	(46.0	)		$	(75.8	)		$	(32.5	)

Schedule of Pre-tax Net Realized and Unrealized Gains (Losses) on Equity Securities

The following table provides pre-tax net realized and unrealized gains (losses) on equity securities recognized in income:

YEARS ENDED DECEMBER 31		2025				2024				2023
(in millions)
On securities still held		$	18.4			$	14.2			$	6.0
On securities sold during the period			0.6				—				(11.6	)
Total net realized and unrealized gains (losses) on equity securities recognized in income		$	19.0			$	14.2			$	(5.6	)

Schedule of Allowance for Credit Losses

The following table provides rollforwards of the allowance for credit losses on mortgage loans:

YEARS ENDED DECEMBER 31		2025				2024
(in millions)
Allowance for credit losses as of the beginning of the period		$	5.7			$	10.0
Reductions for disposals			(0.5	)			(3.6	)
Reductions for writedowns			—				(3.0	)
Additional credit losses on investments for which an allowance was previously recognized			2.9				2.3
Allowance for credit losses as of the end of the period		$	8.1			$	5.7

Schedule of Realized Gain (Loss)

The proceeds from sales of available-for-sale fixed maturities, and the gross realized gains and gross realized losses on those sales, were as follows:

YEARS ENDED DECEMBER 31		2025				2024				2023
(in millions)
Proceeds from sales		$	1,452.9			$	1,844.1			$	168.8
Gross gains			2.4				2.5				1.0
Gross losses			64.6				91.3				10.5

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