Commitments and Contingencies	6 Months Ended
Commitments and Contingencies	Jun. 30, 2025
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Text Block]	13. Commitments and Contingencies Management evaluates each contingent matter separately. A loss is recorded if probable and reasonably estimable. Management establishes liabilities for these contingencies at its “best estimate,” or, if no one number within the range of possible losses is more probable than any other, the Company records an estimated liability at the low end of the range of losses. Litigation The Hartford is involved in claims litigation arising in the ordinary course of business, both as a liability insurer defending or providing indemnity for third-party claims brought against insureds and as an insurer defending coverage claims brought against it. The Hartford accounts for such activity through the establishment of unpaid loss and loss adjustment expense reserves. Subject to the uncertainties related to sexual molestation and sexual abuse claims, including those discussed in Note 9 - Reserve for Unpaid Losses and Loss Adjustment Expenses of this Form 10-Q and in Note 10 - Reserve for Unpaid Losses and Loss Adjustment Expenses, of the Company's Annual Report on Form 10-K for the year ended December 31, 2024, and in the following discussion under the caption “Run-off Asbestos and Environmental Claims,” management expects that the ultimate liability, if any, with respect to such ordinary-course claims litigation, after consideration of provisions made for potential losses and costs of defense, will not be material to the consolidated financial condition, results of operations or cash flows of The Hartford. The Hartford is also involved in other kinds of legal actions, some of which assert claims for substantial amounts. In addition to the matter described below, these actions include putative class actions seeking certification of a state or national class. Such putative class actions have alleged, for example, underpayment of claims or improper sales or underwriting practices in connection with various kinds of insurance policies, such as personal and commercial automobile and property. The Hartford also is involved in individual actions in which punitive damages are sought, such as claims alleging bad faith in the handling of insurance claims or other allegedly unfair or improper business practices. Management expects that the ultimate liability, if any, with respect to such lawsuits, after consideration of provisions made for estimated losses, will not be material to the consolidated financial condition of The Hartford. Nonetheless, given the large or indeterminate amounts sought in certain of these actions, and the inherent unpredictability of litigation, the outcome in certain matters could, from time to time, have a material adverse effect on the Company’s results of operations or cash flows in particular quarterly or annual periods. Run-off Asbestos and Environmental Claims The Company continues to receive A&E claims. Asbestos claims relate primarily to bodily injuries asserted by people who came in contact with asbestos or products containing asbestos. Environmental claims relate primarily to pollution and related clean-up costs. The vast majority of the Company's exposure to A&E relates to accident years prior to 1986 that are reported in Property & Casualty Other Operations ("Run-off A&E"). In addition, since 1986, the Company has written A&E exposures under general liability policies and pollution liability under homeowners policies, which are reported in the Business Insurance and Personal Insurance segments, respectively. Prior to 1986, the Company wrote several different categories of insurance contracts that may cover A&E claims. First, the Company wrote primary policies providing the first layer of coverage in an insured’s liability program. Second, the Company wrote excess and umbrella policies providing higher layers of coverage for losses that exhaust the limits of underlying coverage. Third, the Company acted as a reinsurer assuming a portion of those risks assumed by other insurers writing primary, excess, umbrella and reinsurance coverages. Significant uncertainty limits the ability of insurers and reinsurers to estimate the ultimate reserves necessary for unpaid gross losses and expenses related to environmental and asbestos claims. The degree of variability of gross reserve estimates for these exposures is significantly greater than for other more traditional exposures. In the case of the reserves for asbestos exposures, factors contributing to the high degree of uncertainty include inadequate loss development patterns, plaintiffs’ expanding theories of liability, the risks inherent in major litigation, and inconsistent and emerging legal doctrines with respect to the underlying claims and with respect to the Company's coverage obligations. Furthermore, over time, insurers, including the Company, have experienced significant changes in the rate at which asbestos claims are brought, the claims experience of particular insureds, and the value of claims, making predictions of future exposure from past experience uncertain. Plaintiffs and insureds also have sought to use bankruptcy proceedings, including “pre-packaged” bankruptcies, to accelerate and increase loss payments by insurers. In addition, some policyholders have asserted new classes of claims for coverages to which an aggregate limit of liability may not apply. Further uncertainties include insolvencies of other carriers, insolvencies of insureds and unanticipated developments pertaining to the Company’s ability to recover reinsurance for A&E claims. Management believes these issues are not likely to be resolved in the near future. In the case of the reserves for environmental exposures, factors contributing to the high degree of uncertainty include expanding theories of liability and damages against insureds, emerging risks from products and substances alleged to cause damage, such as per-and polyfluoroalkyl substances ("PFAS"), the risks inherent in major litigation, inconsistent and emerging legal doctrines concerning the existence and scope of coverage for environmental claims, and the scope and level of complexity of the remediation required by regulators. The reporting pattern for assumed reinsurance claims, including those related to A&E claims, is much longer than for direct claims. In many instances, it takes months or years to determine that the policyholder’s own obligations have been met and how the reinsurance in question may apply to such claims. The delay in reporting reinsurance claims and exposures adds to the uncertainty of estimating the related reserves. It is also not possible to predict changes in the legal and legislative environment and their effect on the future development of A&E claims. Given the factors described above, the Company believes the actuarial tools and other techniques it employs to estimate the ultimate cost of claims for more traditional kinds of insurance exposure are less precise in estimating reserves for A&E exposures. For this reason, the Company principally relies on exposure-based analysis to estimate the ultimate costs of these claims, both gross and net of reinsurance, and regularly evaluates new account information in assessing its potential A&E exposures. The Company supplements this exposure-based analysis with evaluations of the Company’s historical direct net loss and expense paid and reported experience, and net loss and expense paid and reported experience by calendar and/or report year, to assess any emerging trends, fluctuations or characteristics suggested by the aggregate paid and reported activity. For its Run-off A&E claims, as of June 30, 2025, the Company reported $141 of net A&E reserves, including the benefit of losses ceded to the A&E ADC with NICO. In addition, the Company has recorded a $850 deferred gain within other liabilities for losses economically ceded to NICO but for which the benefit is not recognized in earnings until later periods. While the Company believes that its current Run-off A&E reserves are appropriate, significant uncertainties limit our ability to estimate the ultimate reserves necessary for unpaid losses and related expenses. The ultimate liabilities, thus, could exceed the currently recorded reserves, and any such additional liability, while not reasonably estimable now, could be material to The Hartford's consolidated operating results or liquidity. The Company’s A&E ADC reinsurance agreement reinsures substantially all A&E reserve development for 2016 and prior accident years, including Run-off A&E and A&E reserves included in Business Insurance and Personal Insurance. The A&E ADC has a coverage limit of $1.5 billion above the Company’s existing net A&E reserves as of December 31, 2016 of approximately $1.7 billion. As of June 30, 2025, the Company has incurred $1.5 billion in cumulative adverse development on A&E reserves that have been ceded under the A&E ADC treaty, leaving no remaining coverage available for future adverse net reserve development, if any. Cumulative adverse development of A&E claims for accident years 2016 and prior in excess of the treaty limit are absorbed as a charge to earnings by the Company. The effect of future charges could be material to the Company’s consolidated operating results or liquidity. For more information on the A&E ADC, refer to Note 10 - Reserve for Unpaid Losses and Loss Adjustment Expenses of Notes to Consolidated Financial Statements included in the Company's 2024 Form 10-K Annual Report. Derivative Commitments Certain of the Company’s derivative agreements contain provisions that are tied to the financial strength ratings, as set by nationally recognized statistical agencies, of the individual legal entity that entered into the derivative agreement. If the legal entity’s financial strength were to fall below certain ratings, the counterparties to the derivative agreements could, in certain instances, terminate the agreements and demand immediate settlement of all outstanding derivative positions traded under each impacted bilateral agreement. The settlement amount is determined by netting the derivative positions transacted under each agreement. If the termination rights were to be exercised by the counterparties, it could impact the legal entity’s ability to conduct hedging activities by increasing the associated costs and decreasing the willingness of counterparties to transact with the legal entity. The aggregate fair value of all derivative instruments with credit-risk-related contingent features that are in a net liability position as of June 30, 2025 was $57 for which the legal entities have posted collateral of $50 in the normal course of business. Based on derivative contractual terms as of June 30, 2025, a downgrade of the current financial strength ratings by either Moody's or S&P would not require additional assets to be posted as collateral. This requirement could change as a result of changes in our hedging activities or to the extent changes in contractual terms are negotiated. The nature of the additional collateral that we would post, if required, would be primarily in the form of U.S. Treasury bills, U.S. Treasury notes and government agency securities.