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Contractual interest rate for funds borrowed, under the debt agreement.

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Schedule II - Condensed Financial Information of Registrant - Narrative (Details) - USD ($) $ in Millions				12 Months Ended
	Jul. 01, 2025	May 14, 2025	Jun. 09, 2023	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 24, 2025	May 14, 2024	Jun. 17, 2022
Condensed Financial Information of Registrant
Interest paid on debt				$ 395	$ 395	$ 355
Allstate Corporation
Condensed Financial Information of Registrant
Notes due to subsidiaries				0	350
Repayment of notes due to subsidiaries				88	0	1,000
Interest paid on debt				395	$ 395	$ 355
Subsidiaries \| Allstate Corporation
Condensed Financial Information of Registrant
Repayment of notes due to subsidiaries				$ 262
National General Holdings Corp. Acquisitions \| Subsidiaries \| Allstate Corporation \| Notes Receivable
Condensed Financial Information of Registrant
Notes receivable		$ 175					$ 110	$ 350
Note stated interest rate (as a percent)		4.85%					4.03%	5.68%
Repayment of notes due to subsidiaries	$ 175	$ 350
Kennett Capital Inc \| Subsidiaries \| Allstate Corporation
Condensed Financial Information of Registrant
Notes due to subsidiaries								$ 350	$ 1,000
Note stated interest rate (as a percent)								5.57%	1.63%
Repayment of notes due to subsidiaries		$ 350	$ 1,000