v3.26.1

Disposition (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
Disposition (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025	Mar. 31, 2025	Mar. 31, 2026
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Reinsurance recoverable	$ 6,542.0	$ 6,471.3		$ 6,542.0
Future policy benefits and expenses	54.7	55.7		54.7
Loss on sale of business	$ 0.5	10.7	$ 0.0	$ 11.2
Disposal Group, Held-for-Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Reinsurance recoverable		489.4
Future policy benefits and expenses		$ 477.1

Amount of gain (loss) from sale and disposal of integrated set of activities and assets capable of being conducted and managed for purpose of providing return in form of dividend, lower cost, or other economic benefit to investor, owner, member and participant.

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Amount, before effect of reinsurance, of present value of future benefit to be paid to or on behalf of policyholder and related expense less present value of future net premium receivable under insurance contract.

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Amount, after valuation allowance, recoverable under reinsurance contracts including premium paid under reinsurance contracts. Examples include, but are not limited to, settled and unsettled claims, incurred but not reported losses, loss adjustment expense, premium paid, policy benefits and policy reserves.

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ASSURANT, INC. 10-Q