Basis of Presentation (Details)	3 Months Ended
Apr. 01, 2012 week
Basis of Presentation
Number of weeks in each fiscal year	52
Number of weeks in each fiscal quarter	13

Represents the number of weeks in each fiscal quarter.

No definition available.

Name:	wts_NumberOfWeeksInFiscalQuarter
Namespace Prefix:	wts_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration