Segment Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2021 USD ($) segment	Dec. 31, 2021 USD ($) item	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Segment information
Number of geographic segments		3	3
Net sales	$ 1,809.2			$ 1,508.6	$ 1,600.5
Operating income	239.6			181.1	197.1
Interest income				(0.2)	(0.4)
Interest expense	6.3			13.3	14.1
Other (income) expense, net	(0.8)			1.0	(0.5)
INCOME BEFORE INCOME TAXES	234.1			167.0	183.9
Capital expenditures	26.7			43.8	29.2
Depreciation and amortization	45.1			46.5	46.6
Identifiable assets (at end of period)	1,855.6	$ 1,855.6	$ 1,855.6	1,738.2	1,723.1
Property, plant and equipment, net (at end of period)	200.7	200.7	200.7	212.3	200.0
Residential & commercial flow control
Segment information
Net sales	953.0			786.5
HVAC & gas
Segment information
Net sales	558.5			459.6
Drains & water re-use
Segment information
Net sales	183.4			156.3
Water quality
Segment information
Net sales	114.3			106.2
U.S.
Segment information
Net sales	1,123.9			956.5	1,014.0
Property, plant and equipment, net (at end of period)	116.2	116.2	116.2	118.9	112.6
Reportable segments
Segment information
Operating income	289.0			220.0	244.2
Corporate
Segment information
Operating income	(49.4)			(38.9)	(47.1)
Intersegment sales
Segment information
Net sales	158.9			99.0	95.0
Americas
Segment information
Net sales	1,207.2			1,025.7	1,084.1
Capital expenditures	17.6			31.2	18.3
Depreciation and amortization	29.8			29.7	29.3
Identifiable assets (at end of period)	1,133.5	1,133.5	1,133.5	1,075.1	1,102.9
Property, plant and equipment, net (at end of period)	121.3	121.3	121.3	122.9	116.7
Americas | Residential & commercial flow control
Segment information
Net sales	697.4			584.6
Americas | HVAC & gas
Segment information
Net sales	308.6			263.9
Americas | Drains & water re-use
Segment information
Net sales	92.8			75.8
Americas | Water quality
Segment information
Net sales	108.4			101.4
Americas | Reportable segments
Segment information
Operating income	211.0			166.3	187.4
Americas | Intersegment sales
Segment information
Net sales	9.3			8.7	12.1
Europe
Segment information
Net sales	517.4			424.9	451.0
Capital expenditures	8.5			11.4	10.3
Depreciation and amortization	12.6			14.3	14.6
Identifiable assets (at end of period)	584.8	584.8	584.8	537.2	515.2
Property, plant and equipment, net (at end of period)	74.5	74.5	74.5	83.8	77.5
Europe | Residential & commercial flow control
Segment information
Net sales	188.0			157.8
Europe | HVAC & gas
Segment information
Net sales	237.0			184.0
Europe | Drains & water re-use
Segment information
Net sales	87.8			79.4
Europe | Water quality
Segment information
Net sales	4.6			3.7
Europe | Reportable segments
Segment information
Operating income	63.6			50.2	49.9
Europe | Intersegment sales
Segment information
Net sales	29.1			18.9	15.2
APMEA
Segment information
Net sales	84.6			58.0	65.4
Capital expenditures	0.6			1.2	0.6
Depreciation and amortization	2.7			2.5	2.7
Identifiable assets (at end of period)	137.3	137.3	137.3	125.9	105.0
Property, plant and equipment, net (at end of period)	4.9	$ 4.9	$ 4.9	5.6	5.8
APMEA | Residential & commercial flow control
Segment information
Net sales	67.6			44.1
APMEA | HVAC & gas
Segment information
Net sales	12.9			11.7
APMEA | Drains & water re-use
Segment information
Net sales	2.8			1.1
APMEA | Water quality
Segment information
Net sales	1.3			1.1
APMEA | Reportable segments
Segment information
Operating income	14.4			3.5	6.9
APMEA | Intersegment sales
Segment information
Net sales	$ 120.5			$ 71.4	$ 67.7