General (Policies)	3 Months Ended
General (Policies)	Mar. 31, 2024
General [Abstract]
Basis of presentation	Basis of presentation The accompanying condensed consolidated financial statements include the accounts of The Allstate Corporation (the “Corporation”) and its wholly owned subsidiaries, primarily Allstate Insurance Company (“AIC”), a property and casualty insurance company (collectively referred to as the “Company” or “Allstate”) and variable interest entities (“VIEs”) in which the Company is considered a primary beneficiary. These condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). The condensed consolidated financial statements and notes as of March 31, 2024 and for the three month periods ended March 31, 2024 and 2023 are unaudited. The condensed consolidated financial statements reflect all adjustments (consisting only of normal recurring accruals) which are, in the opinion of management, necessary for the fair presentation of the financial position, results of operations and cash flows for the interim periods. Certain amounts have been reclassified to conform to current year presentation. These condensed consolidated financial statements and notes should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s annual report on Form 10-K for the year ended December 31, 2023. The results of operations for the interim periods should not be considered indicative of results to be expected for the full year. All significant intercompany accounts and transactions have been eliminated.
Pending accounting standard	Pending accounting standard Accounting for joint ventures In August 2023, the Financial Accounting Standards Board (“FASB”) issued guidance requiring a joint venture to initially measure assets contributed and liabilities assumed at fair value as of the formation date. The new guidance will be applied prospectively for joint ventures with a formation date on or after January 1, 2025. The impact of the adoption is not expected to be material to the Company’s results of operations or financial position. Segment reporting In November 2023, the FASB issued guidance expanding segment disclosures by requiring disclosure of significant segment expenses that are regularly provided to the chief operating decision maker and included within each reported measure of segment profit or loss, an amount and description of its composition for other segment items, and interim disclosures of reportable segments’ profit or loss and assets. The guidance is effective for annual periods beginning after December 15, 2023 and interim periods beginning after December 15, 2024 and is to be applied retrospectively, with early adoption permitted. The Company is currently evaluating the impact of adopting the guidance to its disclosures. Income tax disclosures In December 2023, the FASB issued guidance enhancing various aspects of income tax disclosures. The guidance requires a tabular reconciliation between statutory and effective income tax expense (benefit) with both amounts and percentages for a list of required categories. For certain required categories where an individual category is at least five percent of the statutory tax amount, the required category must be further broken out by nature and, for foreign tax effects, jurisdiction. Additionally, entities must disclose income taxes paid, net of refunds received, broken out between federal, state and foreign, and amounts paid, net of refunds received, to an individual jurisdiction when five percent or more of the total income taxes paid, net of refunds received. All requirements in the guidance are annual in nature, and the guidance is effective for annual reporting periods beginning after December 15, 2024, with early adoption permitted. The guidance only affects disclosures and will have no impact on the Company’s consolidated financial statements. The Company is currently evaluating the impact of adopting the guidance to its disclosures. Climate disclosures In March 2024, the Securities and Exchange Commission (“SEC”) adopted a final rule requiring registrants to disclose certain climate-related information in their registration statements and annual reports. The rule requires the disclosure of qualitative and quantitative information, with certain information, such as financial statement effects of severe weather events, included in the notes to the audited financial statements. Other disclosure requirements include material climate-related risks, processes to manage and govern those risks, disclosure of targets if the targets materially affect or are reasonably likely to materially affect the Company, and, if material, disclosure of certain greenhouse gas emissions. On April 4, 2024, the SEC issued a voluntary stay of the final rule, pending the outcome of pending litigation. The requirements will be applied prospectively and have phased-in effective dates. For the Company, the Form 10-K for the year ended December 31, 2025, will be the first annual report with new climate-related disclosures. The Company is currently evaluating the impact of adopting the final rule.
Earnings per common share	Basic earnings per common share is computed using the weighted average number of common shares outstanding, including vested unissued participating restricted stock units. Diluted earnings per common share is computed using the weighted average number of common and dilutive potential common shares outstanding. For the Company, dilutive potential common shares consist of outstanding stock options, unvested non-participating restricted stock units and contingently issuable performance stock awards. The effect of dilutive potential common shares does not include the effect of options with an anti-dilutive effect on earnings per common share because their exercise prices exceed the average market price of Allstate common shares during the period or for which the unrecognized compensation cost would have an anti-dilutive effect.