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Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			0 Months Ended
	Mar. 29, 2015	Dec. 31, 2014	Mar. 30, 2014	Dec. 01, 2014
Gross Balance
Balance at the beginning of the period	$ 676.4us-gaap_GoodwillGross		$ 539.3us-gaap_GoodwillGross
Foreign Currency Translation and Other	(27.0)		(0.9)
Balance at the end of the period	649.4us-gaap_GoodwillGross	676.4us-gaap_GoodwillGross	538.4us-gaap_GoodwillGross
Accumulated Impairment Losses
Balance at the beginning of the period	(37.4)		(24.5)
Impairment Loss During the Period		12.9
Balance at the end of the period	(37.4)	(37.4)	(24.5)
Net Goodwill	612.0us-gaap_Goodwill	639.0us-gaap_Goodwill	513.9us-gaap_Goodwill
Business combination
Purchase price allocated to goodwill	612.0us-gaap_Goodwill	639.0us-gaap_Goodwill	513.9us-gaap_Goodwill
Tax benefit on Impairment charge	0wts_TaxBenefitOnImpairmentCharge
Aerco
Accumulated Impairment Losses
Net Goodwill				174.3
Business combination
Aggregate consideration, net				272.2
Purchase price allocated to goodwill				174.3
Purchase price allocated to intangible assets				102.4
Americas
Gross Balance
Balance at the beginning of the period	398.0		224.7
Foreign Currency Translation and Other	(0.7)		(0.4)
Balance at the end of the period	397.3		224.3
Accumulated Impairment Losses
Balance at the beginning of the period	(24.5)		(24.5)
Balance at the end of the period	(24.5)		(24.5)
Net Goodwill	372.8		199.8
Business combination
Purchase price allocated to goodwill	372.8		199.8
EMEA
Gross Balance
Balance at the beginning of the period	265.5		301.3
Foreign Currency Translation and Other	(26.3)		(0.1)
Balance at the end of the period	239.2		301.2
Accumulated Impairment Losses
Net Goodwill	239.2		301.2
Business combination
Purchase price allocated to goodwill	239.2		301.2
Asia Pacific
Gross Balance
Balance at the beginning of the period			13.3
Foreign Currency Translation and Other			(0.4)
Balance at the end of the period	12.9	12.9	12.9
Accumulated Impairment Losses
Balance at the end of the period	(12.9)	(12.9)
Net Goodwill			12.9
Business combination
Purchase price allocated to goodwill			$ 12.9