| Cover | Nov. 15, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Nov. 15, 2020 |
| Entity File Number | 001-32316 |
| Entity Registrant Name | B&G Foods, Inc. |
| Entity Central Index Key | 0001278027 |
| Entity Tax Identification Number | 13-3918742 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | Four Gatehall Drive |
| Entity Address, City or Town | Parsippany |
| Entity Address, State or Province | NJ |
| Entity Address, Postal Zip Code | 07054 |
| City Area Code | 973 |
| Local Phone Number | 401-6500 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $0.01 per share |
| Trading Symbol | BGS |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
