Accumulated Other Comprehensive Income (Tables)

12 Months Ended

Dec. 31, 2025

Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]

Schedule of Accumulated Other Comprehensive Income (Loss)

Components of AOCI, after tax, and related changes are as follows:

	Net Unrealized Loss on Securities		Effect of Change in Discount Rate Assumptions on the LFPB1		Net Loss on Derivatives		Foreign Currency Translation Adjustment		Unrecognized Pension and Postretirement Benefit Costs		Total
	(in millions of dollars)
Balance at December 31, 2022	$	(3,028.4)	$	313.9	$	(9.6)	$	(390.1)	$	(334.1)	$	(3,448.3)
Other Comprehensive Income (Loss) Before Reclassifications	1,069.3		(962.3)		(37.4)		69.0		(16.9)		121.7
Amounts Reclassified from AOCI	40.0		—		(26.7)		—		5.3		18.6
Net Other Comprehensive Income (Loss)	1,109.3		(962.3)		(64.1)		69.0		(11.6)		140.3
Balance at December 31, 2023	(1,919.1)		(648.4)		(73.7)		(321.1)		(345.7)		(3,308.0)
Other Comprehensive Income (Loss) Before Reclassifications	(870.4)		1,833.8		(184.4)		(21.9)		(7.4)		749.7
Amounts Reclassified from AOCI	34.3		—		(12.6)		—		12.9		34.6
Net Other Comprehensive Income (Loss)	(836.1)		1,833.8		(197.0)		(21.9)		5.5		784.3
Balance at December 31, 2024	(2,755.2)		1,185.4		(270.7)		(343.0)		(340.2)		(2,523.7)
Other Comprehensive Income (Loss) Before Reclassifications	655.9		(255.5)		(4.1)		97.4		35.7		529.4
Amounts Reclassified from AOCI	96.2		—		(4.0)		—		93.6		185.8
Net Other Comprehensive Income (Loss)	752.1		(255.5)		(8.1)		97.4		129.3		715.2
Balance at December 31, 2025	$	(2,003.1)	$	929.9	$	(278.8)	$	(245.6)	$	(210.9)	$	(1,808.5)
1Liability for Future Policy Benefits

Schedule of Reclassification out of Accumulated Other Comprehensive Income (Loss)

Amounts reclassified from AOCI were recognized in our consolidated statements of income as follows:

	Year Ended December 31
	2025		2024		2023
	(in millions of dollars)
Net Unrealized Loss on Securities
Net Investment Loss on Fixed Maturity Securities
Net Gain (Loss) on Sales	$	41.5	$	(38.2)	$	(48.7)
Impairment Loss	(160.9)		(2.5)		—
Change in Allowance for Credit Losses1	(3.1)		(3.0)		(2.2)
	(122.5)		(43.7)		(50.9)
Income Tax Benefit	(26.3)		(9.4)		(10.9)
Total	$	(96.2)	$	(34.3)	$	(40.0)
Net Loss on Derivatives
Net Investment Income
Gain on Interest Rate Swaps and Forwards	$	6.7	$	16.4	$	34.7
Loss on Foreign Currency Interest Rate Swaps	(0.1)		(0.2)		(0.5)
Net Investment Loss
Loss on Interest Rate Swaps and Forwards	(0.9)		—		—
Loss on Foreign Currency Interest Rate Swaps	(0.6)		(0.2)		(0.4)
	5.1		16.0		33.8
Income Tax Expense	1.1		3.4		7.1
Total	$	4.0	$	12.6	$	26.7
Unrecognized Pension and Postretirement Benefit Costs
Other Expenses
Amortization of Net Actuarial Loss	$	(16.6)	$	(16.4)	$	(7.2)
Amortization of Prior Service Credit	0.3		0.1		0.2
Settlement Loss	(103.8)		—		—
	(120.1)		(16.3)		(7.0)
Income Tax Benefit	(26.5)		(3.4)		(1.7)
Total	$	(93.6)	$	(12.9)	$	(5.3)