CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Cash Flows from Operating Activities
Net Income	$ 232.0	$ 189.1
Adjustments to Reconcile Net Income to Net Cash Provided (Used) by Operating Activities
Change in Receivables	(33.8)	202.4
Change in Deferred Acquisition Costs	(56.4)	(47.2)
Change in Insurance Reserves and Liabilities	143.5	(59.6)
Change in Income Taxes	71.2	53.3
Change in Other Accrued Liabilities	(69.3)	(203.5)
Non-cash Components of Net Investment Income	(36.1)	(18.3)
Net Investment Loss	5.0	206.8
Depreciation	31.8	30.0
Amortization of the Cost of Reinsurance	45.7	9.6
Other, Net	7.2	(9.0)
Net Cash Provided (Used) by Operating Activities	340.8	353.6
Cash Flows from Investing Activities
Proceeds from Sales of Fixed Maturity Securities	45.7	255.4
Proceeds from Maturities of Fixed Maturity Securities	648.0	467.0
Proceeds from Sales and Maturities of Other Investments	140.6	131.8
Purchases of Fixed Maturity Securities	(1,543.0)	(416.8)
Purchases of Other Investments	(88.7)	(98.8)
Net Sales and Maturities (Purchases) of Short-term Investments	979.1	(391.4)
Net Increase (Decrease) in Payables for Collateral on Investments	(59.4)	76.5
Net Purchases of Property and Equipment	(39.6)	(35.8)
Net Cash Provided (Used) by Investing Activities	82.7	(12.1)
Cash Flows from Financing Activities
Repayments of Long-term Debt	7.2	0.0
Issuance of Common Stock	1.6	1.4
Repurchase of Common Stock	(398.8)	(200.5)
Dividends Paid to Stockholders	(78.2)	(77.1)
Proceeds from Policyholder Account Deposits	153.8	32.3
Payments for Policyholder Account Withdrawals	(43.0)	(22.7)
Other, Net	(17.3)	0.0
Net Cash Used by Financing Activities	(389.1)	(266.6)
Net Increase in Cash and Bank Deposits	34.4	74.9
Cash and Bank Deposits at Beginning of Year	158.2	162.8	$ 162.8
Cash and Bank Deposits at End of Period	$ 192.6	$ 237.7	$ 158.2