Document and Entity Information - shares	9 Months Ended
	Sep. 27, 2015	Nov. 02, 2015
Entity Registrant Name	WATTS WATER TECHNOLOGIES INC
Entity Central Index Key	0000795403
Document Type	10-Q
Document Period End Date	Sep. 27, 2015
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q3
Class A
Entity Common Stock, Shares Outstanding		28,133,911
Class B
Entity Common Stock, Shares Outstanding		6,379,290