Income Taxes (Details) - USD ($)	3 Months Ended	9 Months Ended
Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Income Tax Contingency [Line Items]
Income tax expense (benefit) attributable to Kemper Corporation	$ (7,900,000)	$ 18,900,000	$ 34,000,000.0	$ 53,400,000
Effective income tax rate reconciliation, percent	27.30%	20.40%	18.30%	19.50%
Unrecognized Tax Benefits	$ 0		$ 0		$ 0
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	$ 0	$ 0	0	$ 0
Income Tax Paid, Federal, after Refund Received			20,500,000	9,900,000
Income Tax Paid, State and Local, after Refund Received			1,700,000	600,000
Foreign Tax Jurisdiction
Income Tax Contingency [Line Items]
Proceeds from Income Tax Refunds			$ 0	$ 0

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Income Tax Expense (Benefit) Attributable to Parent

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount, after income tax refund received, of cash paid to federal (national) tax jurisdiction for tax on income.

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Amount, after income tax refund received, of cash paid to state and local tax jurisdictions for tax on income.

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Amount of income tax refund received from tax jurisdiction.

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Amount of unrecognized tax benefits.

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Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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