| Document and Entity Information | Sep. 14, 2023 |
| Document And Entity Information [Line Items] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001848020 |
| Document Type | 8-K |
| Document Period End Date | Sep. 14, 2023 |
| Entity Registrant Name | BLACK MOUNTAIN ACQUISITION CORP. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-40907 |
| Entity Tax Identification Number | 86-2013849 |
| Entity Address, Address Line One | 425 Houston Street |
| Entity Address, Address Line Two | Suite 400 |
| Entity Address, City or Town | Fort Worth |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 76102 |
| City Area Code | (817) |
| Local Phone Number | 698-9901 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Units Each Consisting Of One Share Of Class A Common Stock 0.0001 Par Value And Three Quarters Of One Warrant [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Units, each consisting of one share of Class A Common Stock, $0.0001 par value, and three quarters of one warrant |
| Trading Symbol | BMAC.U |
| Security Exchange Name | NYSE |
| Common Stock [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Class A Common Stock, par value $0.0001 per share |
| Trading Symbol | BMAC |
| Security Exchange Name | NYSE |
| Warrants Each Whole Warrant Exercisable For One Share Of Class A Common Stock [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Warrants, each whole warrant exercisable for one share of Class A Common Stock |
| Trading Symbol | BMAC WS |
| Security Exchange Name | NYSE |
