Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	Apr. 28, 2019
Entity Registrant Name	WATTS WATER TECHNOLOGIES INC
Entity Central Index Key	0000795403
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Filer Category	Large Accelerated Filer
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Class A
Entity Common Stock, Shares Outstanding		27,692,316
Class B
Entity Common Stock, Shares Outstanding		6,279,290