Revenue Recognition (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($)	Jul. 01, 2018 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2019 segment	Jun. 30, 2019 item	Jul. 01, 2018 USD ($)
Disaggregation of Revenue
Number of distribution channels | item					4
Number of geographic segments				3	3
Revenue	$ 416.8	$ 407.9	$ 805.5			$ 786.4
Wholesale
Disaggregation of Revenue
Revenue	252.8	246.0	490.5			478.0
OEM
Disaggregation of Revenue
Revenue	59.6	58.3	117.0			117.4
Specialty
Disaggregation of Revenue
Revenue	88.6	87.7	164.9			156.5
DIY
Disaggregation of Revenue
Revenue	15.8	15.9	33.1			34.5
Residential & commercial flow control
Disaggregation of Revenue
Revenue	216.5	208.9	420.1			405.6
HVAC & gas
Disaggregation of Revenue
Revenue	129.3	135.0	248.5			255.7
Drainage & water re-use
Disaggregation of Revenue
Revenue	45.7	41.9	86.2			80.3
Water quality
Disaggregation of Revenue
Revenue	25.3	22.1	50.7			44.8
Americas
Disaggregation of Revenue
Revenue	287.0	272.0	545.9			513.1
Americas | Wholesale
Disaggregation of Revenue
Revenue	162.0	150.6	307.6			287.2
Americas | OEM
Disaggregation of Revenue
Revenue	21.9	20.1	42.7			39.2
Americas | Specialty
Disaggregation of Revenue
Revenue	87.9	86.1	163.9			153.7
Americas | DIY
Disaggregation of Revenue
Revenue	15.2	15.2	31.7			33.0
Americas | Residential & commercial flow control
Disaggregation of Revenue
Revenue	161.3	151.0	308.7			290.9
Americas | HVAC & gas
Disaggregation of Revenue
Revenue	79.8	80.6	148.5			143.1
Americas | Drainage & water re-use
Disaggregation of Revenue
Revenue	21.6	18.9	39.7			35.4
Americas | Water quality
Disaggregation of Revenue
Revenue	24.3	21.5	49.0			43.7
Europe
Disaggregation of Revenue
Revenue	113.2	117.1	229.5			240.1
Europe | Wholesale
Disaggregation of Revenue
Revenue	75.2	78.5	154.7			161.2
Europe | OEM
Disaggregation of Revenue
Revenue	37.4	37.9	73.4			77.4
Europe | DIY
Disaggregation of Revenue
Revenue	0.6	0.7	1.4			1.5
Europe | Residential & commercial flow control
Disaggregation of Revenue
Revenue	43.6	44.7	89.1			92.0
Europe | HVAC & gas
Disaggregation of Revenue
Revenue	45.9	49.4	94.3			103.3
Europe | Drainage & water re-use
Disaggregation of Revenue
Revenue	23.0	22.6	44.9			44.2
Europe | Water quality
Disaggregation of Revenue
Revenue	0.7	0.4	1.2			0.6
APMEA
Disaggregation of Revenue
Revenue	16.6	18.8	30.1			33.2
APMEA | Wholesale
Disaggregation of Revenue
Revenue	15.6	16.9	28.2			29.6
APMEA | OEM
Disaggregation of Revenue
Revenue	0.3	0.3	0.9			0.8
APMEA | Specialty
Disaggregation of Revenue
Revenue	0.7	1.6	1.0			2.8
APMEA | Residential & commercial flow control
Disaggregation of Revenue
Revenue	11.6	13.2	22.3			22.7
APMEA | HVAC & gas
Disaggregation of Revenue
Revenue	3.6	5.0	5.7			9.3
APMEA | Drainage & water re-use
Disaggregation of Revenue
Revenue	1.1	0.4	1.6			0.7
APMEA | Water quality
Disaggregation of Revenue
Revenue	$ 0.3	$ 0.2	$ 0.5			$ 0.5