Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011 product segment	Dec. 31, 2010	Dec. 31, 2009
Segment Information
Number of geographic segments									3
Segment information
Net sales	$ 360.2	$ 370.8	$ 375.7	$ 329.9	$ 316.7	$ 314.6	$ 324.0	$ 319.3	$ 1,436.6	$ 1,274.6	$ 1,225.9
Operating income (loss)									117.1	114.2	92.2
Interest income									1.0	1.0	0.9
Interest expense									(25.8)	(22.8)	(22.0)
Other									(0.8)	2.1	1.2
Income from continuing operations before income taxes									91.5	94.5	72.3
Identifiable Assets (at year end)	1,697.5				1,646.1				1,697.5	1,646.1	1,599.2
Long-Lived Assets (at year end)	226.7				197.5				226.7	197.5	206.5
Capital Expenditures									22.7	24.6	24.2
Depreciation and Amortization									51.4	44.8	46.8
Intersegment sales									144.6	127.0	119.8
Number of product categories									4
Residential & commercial flow control
Segment information
Net sales									755.4	652.2	623.4
HVAC & gas
Segment information
Net sales									475.7	433.4	423.5
Drains & water re-use
Segment information
Net sales									135.2	122.2	117.6
Water quality
Segment information
Net sales									70.3	66.8	61.4
Reportable Segments
Segment information
Operating income (loss)									152.9	149.6	123.0
North America
Segment information
Net sales									819.4	785.5	738.5
Operating income (loss)									112.0	106.4	78.6
Identifiable Assets (at year end)	831.8				871.8				831.8	871.8	804.7
Long-Lived Assets (at year end)	78.4				77.4				78.4	77.4	81.5
Capital Expenditures									8.4	9.1	9.3
Depreciation and Amortization									19.2	17.9	17.9
Intersegment sales									3.3	3.6	3.6
North America | U.S.
Segment information
Net sales									741.4	712.2	672.6
Long-Lived Assets (at year end)	73.5				72.4				73.5	72.4	74.8
Europe
Segment information
Net sales									595.5	468.3	466.5
Operating income (loss)									28.7	43.7	51.0
Identifiable Assets (at year end)	773.2				692.8				773.2	692.8	686.0
Long-Lived Assets (at year end)	133.3				104.6				133.3	104.6	108.5
Capital Expenditures									13.6	14.8	14.4
Depreciation and Amortization									30.2	24.9	23.1
Intersegment sales									8.4	7.6	5.8
Asia
Segment information
Net sales									21.7	20.8	20.9
Operating income (loss)									12.2	(0.5)	(6.6)
Identifiable Assets (at year end)	92.5				79.7				92.5	79.7	85.4
Long-Lived Assets (at year end)	15.0				15.5				15.0	15.5	16.5
Capital Expenditures									0.7	0.7	0.5
Depreciation and Amortization									2.0	2.0	5.8
Intersegment sales									132.9	115.8	110.4
Corporate
Segment information
Operating income (loss)									(35.8)	(35.4)	(30.8)
Charges related to separation agreement with company's former CEO									6.3
Discontinued operations
Segment information
Identifiable Assets (at year end)					$ 1.8					$ 1.8	$ 23.1