| Document and Entity Information | Oct. 14, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Oct. 14, 2020 |
| Entity Registrant Name | SLEEP NUMBER CORP |
| Entity Central Index Key | 0000827187 |
| Amendment Flag | false |
| Entity Incorporation, State or Country Code | MN |
| Entity File Number | 000-25121 |
| Entity Tax Identification Number | 41-1597886 |
| Entity Address, Address Line One | 1001 Third Avenue South |
| Entity Address, City or Town | Minneapolis |
| Entity Address, State or Province | MN |
| Entity Address, Postal Zip Code | 55404 |
| City Area Code | 763 |
| Local Phone Number | 551-7000 |
| 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 | SNBR |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
