| Cover | Feb. 14, 2024 |
| Document Information [Line Items] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Feb. 14, 2024 |
| Entity File Number | 001-40158 |
| Entity Registrant Name | ATLANTIC COASTAL ACQUISITION CORP. |
| Entity Central Index Key | 0001836274 |
| Entity Tax Identification Number | 85-4178663 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 1 Woodbury Mews |
| Entity Address, Address Line Two | Dun Laoghaire |
| Entity Address, City or Town | Dublin |
| Entity Address, Country | IE |
| Entity Address, Postal Zip Code | A96 ED72 |
| City Area Code | 353 |
| Local Phone Number | 8706 50447 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | false |
| Units, each consisting of one share of Class A common stock, $0.0001 par value, and one-third of one redeemable warrant [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Units, each consisting of one share of Class A common stock, $0.0001 par value, and one-third of one redeemable warrant |
| Trading Symbol | ACAHU |
| Security Exchange Name | NASDAQ |
| Shares of Class A common stock included as part of the units [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Shares of Class A common stock included as part of the units |
| Trading Symbol | ACAH |
| Security Exchange Name | NASDAQ |
| Warrant [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Warrants included as part of the units, each whole warrant exercisable for one share of Class A common stock at an exercise price of $11.50 |
| Trading Symbol | ACAHW |
| Security Exchange Name | NASDAQ |
