| Document and Entity Information | Oct. 30, 2019 |
| Document and Entity Information [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Oct. 30, 2019 |
| Entity File Number | 001-11499 |
| Entity Registrant Name | WATTS WATER TECHNOLOGIES INC |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 04-2916536 |
| Entity Address, Address Line One | 815 Chestnut Street |
| Entity Address, City or Town | North Andover |
| Entity Address, State or Province | MA |
| Entity Address, Postal Zip Code | 01845 |
| City Area Code | 978 |
| Local Phone Number | 688-1811 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000795403 |
| Amendment Flag | false |
