| Cover Page Document | Aug. 21, 2023 |
| Document Information [Line Items] | |
| Amendment Flag | false |
| Document Type | 8-K |
| Document Period End Date | Aug. 21, 2023 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Title of 12(b) Security | Common stock, $0.0001 par value per share |
| Entity Registrant Name | AMERICAN COASTAL INSURANCE CORPORATION |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-35761 |
| Entity Tax Identification Number | 75-3241967 |
| Entity Address, Address Line One | 800 2nd Avenue S. |
| Entity Address, Postal Zip Code | 33701 |
| Entity Address, City or Town | Saint Petersburg, |
| Entity Address, State or Province | FL |
| City Area Code | (727) |
| Local Phone Number | 895-7737 |
| Trading Symbol | ACIC |
| Security Exchange Name | NASDAQ |
| Entity Central Index Key | 0001401521 |
