| Document and Entity Information | May 03, 2022 |
| Document and Entity Information [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001766368 |
| Document Type | 8-K |
| Document Period End Date | May 3, 2022 |
| Entity Registrant Name | Mayville Engineering Company, Inc. |
| Entity Incorporation, State or Country Code | WI |
| Entity File Number | 001-38894 |
| Entity Tax Identification Number | 39-0944729 |
| Entity Address, Address Line One | 715 South Street |
| Entity Address, City or Town | Mayville |
| Entity Address State Or Province | WI |
| Entity Address, Postal Zip Code | 53050 |
| City Area Code | (920) |
| Local Phone Number | 387-4500 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, no par value |
| Trading Symbol | MEC |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
