Consolidated Statements of Cash Flows - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash Flows from Operating Activities:
Net Income (Loss)		$ 312.5	$ (272.3)	$ (286.6)
Adjustments to Reconcile Net Income (Loss) to Net Cash Provided by (Used in) Operating Activities:
Net Realized Gain on Sale of Investments		(13.2)	18.6	(4.3)
Impairment Losses		5.8	1.1	25.8
Depreciation and Amortization of Property, Equipment, Software and Intangible Assets Acquired		53.7	58.6	70.9
Settlement Costs Related to Defined Benefit Pension Plan		(2.6)	70.2	0.0
Loss from Early Extinguishment of Debt		0.0	0.0	3.7
Equity Securities, FV-NI, Gain (Loss)		2.7	(4.7)	79.9
Goodwill Impairment		0.0	49.6	0.0
Pension Plan assets reverted to the Company		13.1	0.0	0.0
Changes in:
Receivables from Policyholders		(25.9)	326.4	129.4
Reinsurance Recoverables		7.0	12.1	(1.9)
Deferred Policy Acquisition Costs		(38.3)	43.9	14.2
Insurance Reserves		(2.3)	(30.8)	26.5
Unearned Premiums		(26.0)	(403.1)	(183.5)
Income Taxes		65.3	33.2	(83.6)
Other		2.3	(33.0)	(11.2)
Net Cash Provided by (Used in) Operating Activities		382.9	(134.2)	(210.3)
Cash Flows from Investing Activities:
Proceeds from the Sales, Calls and Maturities of Fixed Maturities		1,316.5	673.0	1,295.5
Equity Securities		37.8	149.0	536.0
Real Estate Investments		3.7	0.0	0.0
Mortgage Loans		121.6	95.2	91.3
Other Investments		21.8	18.3	52.1
Fixed Maturities		(1,012.5)	(447.4)	(1,815.8)
Equity Securities		(19.4)	(44.4)	(58.9)
Real Estate Investments		(1.6)	(1.0)	(3.1)
Corporate-Owned Life Insurance		(3.5)	0.0	(110.0)
Mortgage Loans		(109.7)	(104.1)	(81.1)
Other Investments		(51.2)	(19.8)	(13.0)
Net (Purchases) Sales of Short-term Investments		(521.0)	(238.4)	6.1
Sale of Reserve National, Net of Cash Disposed		0.0	0.0	14.8
Acquisition of Software and Long-lived Assets		(53.2)	(53.8)	(30.8)
Settlement Proceeds from Company-Owned Life Insurance		13.5	102.2	0.0
Other		12.8	(20.9)	8.5
Net Cash (Used in) Provided by Investing Activities		(244.4)	107.9	(108.4)
Cash Flows from Financing Activities:
Repayments of Long-term Debt		0.0	0.0	(280.0)
Proceeds from Issuance of 5.875% Fixed-Rate Reset Junior Subordinated Debentures Due 2062		0.0	0.0	145.6
Proceeds from Policyholder Contract Obligations		102.2	123.3	335.5
Repayment of Policyholder Contract Obligations		(120.6)	(169.0)	(138.2)
Proceeds from Shares Issued under Employee Stock Purchase Plan		3.8	4.3	4.9
Common Stock Repurchases		(38.9)	0.0	0.0
Dividends Paid		(80.1)	(80.1)	(79.7)
Other		(3.6)	(0.5)	0.6
Net Cash (Used in) Provided by Financing Activities		(137.2)	(122.0)	382.9
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect, Total	[1]	1.3	(148.3)	64.2
Cash, Beginning of Year1	[1]	64.1	212.4	148.2
Cash, End of Year1	[1]	65.4	64.1	212.4
Cash (paid) received during the year for:
Interest		(54.5)	(54.5)	(51.5)
Income taxes paid		(11.2)	106.7	(0.7)
Operating Leases		(21.6)	(25.4)	(24.0)
Non-Cash Activities:
Right-of-Use Assets Obtained in Exchange for New Operating Lease Liabilities		9.5	13.8	9.7
Real estate acquired via mortgage loan foreclosure		10.9	0.0	0.0
Equity Method Limited Liability Investments
Adjustments to Reconcile Net Income (Loss) to Net Cash Provided by (Used in) Operating Activities:
Change in Value of Alternative Energy Partnership Investments		31.1	(1.1)	(9.5)
Alternative Energy Partnership Investments
Adjustments to Reconcile Net Income (Loss) to Net Cash Provided by (Used in) Operating Activities:
Change in Value of Alternative Energy Partnership Investments		(2.3)	(2.9)	19.9
Senior Notes, 3.800 Percent Due February 23, 2032
Cash Flows from Financing Activities:
Proceeds from Issuance of 3.800% Senior Notes due February 23, 2032		0.0	0.0	396.3
Issue Fess		0.0	0.0	(1.2)
5.875% Fixed-Rate Reset Junior Subordinated Debentures due 2062
Cash Flows from Financing Activities:
Issue Fess		$ 0.0	$ 0.0	$ (0.9)

[1] 1Includes amounts attributable to Kemper Reciprocal reported as non-controlling interest.