| Document and Entity Information | Mar. 04, 2021 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001092796 |
| Document Type | 8-K |
| Document Period End Date | Mar. 4, 2021 |
| Entity Registrant Name | Smith & Wesson Brands, Inc. |
| Entity Incorporation State Country Code | NV |
| Entity File Number | 001-31552 |
| Entity Tax Identification Number | 87-0543688 |
| Entity Address, Address Line One | 2100 Roosevelt Avenue |
| Entity Address, City or Town | Springfield |
| Entity Address, State or Province | MA |
| Entity Address, Postal Zip Code | 01104 |
| City Area Code | (800) |
| Local Phone Number | 331-0852 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, Par Value $0.001 per Share |
| Trading Symbol | SWBI |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
