Organization, Consolidation and Presentation	12 Months Ended
Organization, Consolidation and Presentation	Dec. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation	ORGANIZATION, CONSOLIDATION AND PRESENTATION (a)Business American Coastal Insurance Corporation (referred to in this document as we, our, us, the Company or ACIC) is a property and casualty insurance holding company that sources, writes and services residential commercial and personal property and casualty insurance policies using a network of agents and two wholly owned insurance subsidiaries. On July 10, 2023, we changed our corporate name from United Insurance Holdings Corp. to American Coastal Insurance Corporation. Our two insurance subsidiaries are Interboro Insurance Company (IIC), acquired via acquisition on April 29, 2016; and American Coastal Insurance Company (AmCoastal), acquired via merger on April 3, 2017. Our other subsidiaries include United Insurance Management, L.C. (UIM), a managing general agent; Skyway Claims Services, LLC (SCS), which provides claims adjusting services to our insurance companies; AmCo Holding Company, LLC (AmCo) which is a holding company subsidiary that consolidates its respective insurance company; BlueLine Cayman Holdings (BlueLine), which reinsures portfolios of excess and surplus policies; Shoreline Re, which provides a portion of the reinsurance protection purchased by our insurance subsidiaries when prudent; Skyway Reinsurance Services, LLC, which provides reinsurance brokerage services for our insurance companies; Skyway Legal Services, LLC (SLS), which provides claims litigation services to our insurance companies; and Skyway Underwriters, LLC, a managing general agent that provides technological and distribution services to our insurance companies. Our primary products are commercial and homeowners residential property insurance. We currently offer commercial residential insurance in Florida. During 2022, we also wrote commercial residential insurance in South Carolina and Texas, however, effective May 1, 2022, we no longer write in these states. In addition, we write personal residential insurance in New York. During 2022, we wrote personal residential business in six other states; however, on February 27, 2023, our former insurance subsidiary, United Property & Casualty Insurance Company (UPC) was placed into receivership with the Florida Department of Financial Services (DFS), which divested our ownership of UPC. The events leading to receivership and results of this subsidiary, now included within discontinued operations, are discussed in Note 4 below. Effective June 1, 2022, we merged our majority-owned insurance subsidiary, Journey Insurance Company (JIC) into AmCoastal, with AmCoastal being the surviving entity. JIC was formed in strategic partnership with a subsidiary of Tokio Marine Kiln Group Limited (Kiln) on August 30, 2018 and operated independently from AmCoastal prior to the merging of the entities. The Kiln subsidiary held a noncontrolling interest in JIC, which was terminated prior to the merger. On May 9, 2024, the Company entered into a Stock Purchase Agreement (the "Sale Agreement") with Forza Insurance Holdings, LLC ("Forza") in which ACIC will sell and Forza will acquire 100% of the issued and outstanding stock of IIC. The aggregate purchase price for the shares will be equal to IIC's GAAP shareholder’s equity on the closing date. Closing is subject to customary closing conditions, including New York Department of Financial Services ("NYDFS") approval of Forza's application for acquisition of control, and NYDFS approval of a new rate and form filing. On February 13, 2025, Forza’s application to acquire IIC was approved by the NYDFS. The Company and Forza have agreed to close on April 1, 2025. Given IIC is our last remaining personal lines entity and represents the final step in our strategic shift to becoming a specialty commercial underwriter, IIC results of operations and assets and liabilities are captured within discontinued operations and can be seen in Note 4 of the Notes to Consolidated Financial Statements below. As a result of the Sale Agreement described above, IIC is presented as discontinued operations. The remaining activity captured within continuing operations supports only our commercial residential insurance offerings. Given this fact pattern, we now conduct our operations under one operating segment, which consists of our commercial lines business. Further information regarding this segment can be seen in Not e 2(j) below. (b)Consolidation and Presentation We prepare our consolidated financial statements in conformity with U.S. generally accepted accounting principles (GAAP). While preparing our consolidated financial statements, we make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the consolidated financial statements, as well as reported amounts of revenues and expenses during the reporting period. Accordingly, actual results could differ from those estimates. Reported amounts that require us to make extensive use of estimates include our reserves for unpaid losses and loss adjustment expenses, investments and goodwill. Except for the captions on our Consolidated Balance Sheets and Consolidated Statements of Comprehensive Income (Loss), we generally use the term loss(es) to collectively refer to both loss and loss adjustment expenses. We include all our subsidiaries in our consolidated financial statements, eliminating intercompany balances and transactions during consolidation. As described in Note 2, our subsidiary, IIC and our former subsidiary, UPC, and activities related directly to supporting the business conducted by UPC qualified as discontinued operations. For the year ended December 31, 2024, we have consolidated our Operating and Underwriting Expenses and General and Administrative Expenses lines within our Consolidated Statements of Comprehensive Income into the General and Administrative Expenses line. This was done in an effort to align more closely with our peer group for comparability. Accordingly, we have recast our Consolidated Statements of Comprehensive Income for the years ended December 31, 2023 and 2022 to align with this format. We have also added a new note to our consolidated financial statements, N ote 3, Disaggregation of Relevant Expense Captions, to provide the users of our financial statements with enhanced insight into this expense line.