| Cover | Dec. 29, 2021 |
| Entity Information [Line Items] | |
| Document Type | 8-K |
| Document Period End Date | Dec. 29, 2021 |
| Entity Registrant Name | BENSON HILL, INC. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-39835 |
| Entity Tax Identification Number | 85-3374823 |
| Entity Address, Address Line One | 1001 North Warson Rd. |
| Entity Address, City or Town | St. Louis |
| Entity Address, State or Province | MO |
| Entity Address, Postal Zip Code | 63132 |
| City Area Code | 314 |
| Local Phone Number | 222-8218 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Entity Central Index Key | 0001830210 |
| Amendment Flag | false |
| Entity Ex Transition Period | false |
| Common stock, $0.0001 par value | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | Common stock, $0.0001 par value |
| Trading Symbol | BHIL |
| Security Exchange Name | NYSE |
| Warrants exercisable for one share of common stock at an exercise price of $11.50 | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | Warrants exercisable for one share of common stock at an exercise price of $11.50 |
| Trading Symbol | BHIL WS |
| Security Exchange Name | NYSE |
