| Document and Entity Information | Sep. 02, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Sep. 2, 2021 |
| Entity Registrant Name | SIGNET JEWELERS LIMITED |
| Entity File Number | 1-32349 |
| Entity Incorporation, State or Country Code | D0 |
| Entity Address, Address Line One | Clarendon House |
| Entity Address, Address Line Two | 2 Church Street |
| Entity Address, City or Town | Hamilton |
| Entity Address, Postal Zip Code | HM11 |
| Entity Address, Country | BM |
| City Area Code | 441 |
| Local Phone Number | 296 5872 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Shares of $0.18 each |
| Trading Symbol | SIG |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000832988 |
| Amendment Flag | false |
