Goodwill and Intangibles - Goodwill (Details) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended	15 Months Ended	21 Months Ended
	Sep. 27, 2020 USD ($)	Sep. 27, 2020 USD ($)	Dec. 31, 2019 USD ($)	Mar. 29, 2020 USD ($) item	Sep. 27, 2020 USD ($) item
Gross Balance
Balance at the beginning of the period		$ 748.2	$ 711.9	$ 711.9	$ 711.9
Acquired During the Period		3.9	38.3
Foreign Currency Translation and Other		3.7	(2.0)
Balance at the end of the period	$ 755.8	755.8	748.2		755.8
Accumulated Impairment Losses
Balance at the beginning of the period		(167.1)	(167.1)	$ (167.1)	(167.1)
Balance at the end of the period	(167.1)	(167.1)	(167.1)		(167.1)
Net Goodwill	588.7	588.7	581.1		$ 588.7
Number of reporting units | item				7	7
Heating and Hot Water Solutions
Gross Balance
Balance at the end of the period	218.9	218.9			$ 218.9
AVG
Gross Balance
Acquired During the Period	3.9
Americas
Gross Balance
Balance at the beginning of the period		476.8	438.1	$ 438.1	438.1
Acquired During the Period			38.3
Foreign Currency Translation and Other		(0.3)	0.4
Balance at the end of the period	476.5	476.5	476.8		476.5
Accumulated Impairment Losses
Balance at the beginning of the period		(24.5)	(24.5)	(24.5)	(24.5)
Balance at the end of the period	(24.5)	(24.5)	(24.5)		(24.5)
Net Goodwill	452.0	452.0	452.3		452.0
Europe
Gross Balance
Balance at the beginning of the period		241.4	243.7	243.7	243.7
Foreign Currency Translation and Other		4.7	(2.3)
Balance at the end of the period	246.1	246.1	241.4		246.1
Accumulated Impairment Losses
Balance at the beginning of the period		(129.7)	(129.7)	(129.7)	(129.7)
Balance at the end of the period	(129.7)	(129.7)	(129.7)		(129.7)
Net Goodwill	116.4	116.4	111.7		116.4
APMEA
Gross Balance
Balance at the beginning of the period		30.0	30.1	30.1	30.1
Acquired During the Period		3.9
Foreign Currency Translation and Other		(0.7)	(0.1)
Balance at the end of the period	33.2	33.2	30.0		33.2
Accumulated Impairment Losses
Balance at the beginning of the period		(12.9)	(12.9)	$ (12.9)	(12.9)
Balance at the end of the period	(12.9)	(12.9)	(12.9)		(12.9)
Net Goodwill	$ 20.3	$ 20.3	$ 17.1		$ 20.3