| Document and Entity Information | Oct. 13, 2020 |
| Document And Entity Information [Line Items] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001644406 |
| Document Type | 8-K |
| Document Period End Date | Oct. 13, 2020 |
| Entity Registrant Name | Hostess Brands, Inc. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 1-37540 |
| Entity Tax Identification Number | 47-4168492 |
| Entity Address, Address Line One | 7905 Quivira Road |
| Entity Address, City or Town | Lenexa |
| Entity Address, State or Province | KS |
| Entity Address, Postal Zip Code | 66215 |
| City Area Code | (816) |
| Local Phone Number | 701-4600 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Common Class A [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Class A Common Stock, Par Value of $0.0001 per share |
| Trading Symbol | TWNK |
| Security Exchange Name | NASDAQ |
| Warrant [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Warrants, each exercisable for a half share of Class A Common Stock |
| Trading Symbol | TWNKW |
| Security Exchange Name | NASDAQ |
