Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Proceedings Lawsuits arise in the ordinary course of the Company’s business. It is the opinion of the Company’s management, based upon the information available, that the expected outcome of litigation against the Company, individually or in the aggregate, will not have a material adverse effect on the Company’s financial position, although an adverse resolution of litigation against the Company in a fiscal quarter or year could have a material adverse effect on the Company’s results of operations or liquidity in that particular quarter or year. In addition, in the ordinary course of their respective businesses, certain of AGL’s insurance subsidiaries are involved in litigation with third parties to recover insurance losses paid in prior periods or prevent or reduce losses in the future. For example, the Company is involved in a number of legal actions in the Federal District Court of Puerto Rico to enforce or defend its rights with respect to the obligations it insures of Puerto Rico and various of its related authorities and public corporations. See the “Exposure to Puerto Rico” section of Note 3, Outstanding Exposure, for a description of such actions. The impact, if any, of these and other proceedings on the amount of recoveries the Company receives and losses it pays in the future is uncertain, and the impact of any one or more of these proceedings during any quarter or year could be material to the Company’s results of operations in that particular quarter or year. In the first quarter of 2023, the Company reduced its previously recorded accrual of $20 million to zero in connection with developments in litigation. The Company also receives subpoenas and interrogatories from regulators from time to time. Accounting Policy The Company establishes accruals for litigation and regulatory matters to the extent it is probable that a loss has been incurred and the amount of that loss can be reasonably estimated. Additionally, it discloses such amounts if material to the financial position of the Company. For litigation and regulatory matters where a loss may be reasonably possible, but not probable, or is probable but not reasonably estimable, no accrual is established, but if the matter is material, it would be disclosed below. The Company reviews relevant information with respect to its litigation and regulatory matters on a quarterly basis and updates its accruals, disclosures, and estimates of reasonably possible loss based on such reviews. Litigation On November 28, 2011, Lehman Brothers International (Europe) (in administration) (LBIE) sued AG Financial Products Inc. (AGFP), an affiliate of AGC, which, in the past, had provided credit protection to counterparties under CDS. AGC acts as the credit support provider of AGFP under these CDS. LBIE’s complaint, which was filed in the Supreme Court of the State of New York (the Court), asserted a claim for breach of the implied covenant of good faith and fair dealing based on AGFP's termination in December 2008 of nine credit derivative transactions between LBIE and AGFP and asserted claims for breach of contract and breach of the implied covenant of good faith and fair dealing based on AGFP’s termination in July 2009 of 28 other credit derivative transactions between LBIE and AGFP and AGFP’s calculation of the termination payment in connection with those 28 other credit derivative transactions. Following defaults by LBIE, AGFP had terminated the transactions in question in compliance with the agreement between AGFP and LBIE, and properly calculated that LBIE owes AGFP approximately $4 million for the claims which were dismissed (as described below) and approximately $21 million in connection with the termination of the other credit derivative transactions, whereas LBIE asserted in the complaint that AGFP owes LBIE a termination payment of approximately $1.4 billion. On March 15, 2013, the Court granted AGFP’s motion to dismiss in respect of the count relating to the nine credit derivative transactions and narrowed LBIE’s claim with respect to the 28 other credit derivative transactions. Following a bench trial, on March 8, 2023, the Court rendered its decision and found in favor of AGFP. On June 30, 2023, the clerk entered judgment in favor of AGFP in the amount of approximately $54 million plus post-judgment simple interest at an annual rate of 8%. On July 1, 2023, AGFP moved the Court to award it approximately $58 million for attorneys’ fees and expenses AGFP incurred through March 2023. The parties reached a confidential settlement with respect to this motion for attorneys’ fees, and AGFP withdrew the motion without prejudice on October 30, 2023. On September 22, 2023, LBIE appealed the Court’s post-trial decision to the New York Appellate Division’s First Judicial Department. Briefing on the appeal was completed on January 12, 2024, and oral argument on the appeal was heard on February 21, 2024. The Company did not accrue in its financial statements for the judgment it was awarded or the attorneys’ fees it sought.