Acquisitions (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended 12 Months Ended
Aug. 31, 2016
Jul. 01, 2016
Jan. 20, 2016
Oct. 01, 2016
Oct. 01, 2016
Dec. 31, 2015
Oct. 03, 2015
Dec. 31, 2014
Business Acquisition [Line Items]                
Goodwill       $ 413.0 $ 413.0 $ 298.7 $ 298.5 $ 296.9
Indoor Cycling Group [Member]                
Business Acquisition [Line Items]                
Business Acquisition, Percentage of Voting Interests Acquired 100.00%              
Business Combination, Consideration Transferred $ 54.1              
Payments to Acquire Businesses, Gross 51.7              
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill 20.4              
Goodwill 26.0              
Indoor Cycling Group [Member] | Customer Relationships [Member]                
Business Acquisition [Line Items]                
Finite-Lived Intangibles [1] 11.2              
Useful Life         11 years      
Indoor Cycling Group [Member] | Patents and proprietary technology                
Business Acquisition [Line Items]                
Finite-Lived Intangibles [1] 3.2              
Useful Life         5 years      
Indoor Cycling Group [Member] | Trade Names [Member]                
Business Acquisition [Line Items]                
Indefinite-Lived Intangible Assets [1] $ 6.0              
Thunder Jet [Member]                
Business Acquisition [Line Items]                
Business Combination, Consideration Transferred   $ 20.9            
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill   10.8            
Goodwill   2.5            
Thunder Jet [Member] | Customer Relationships [Member]                
Business Acquisition [Line Items]                
Finite-Lived Intangibles   5.4            
Useful Life         15 years      
Thunder Jet [Member] | Trade Names [Member]                
Business Acquisition [Line Items]                
Indefinite-Lived Intangible Assets   $ 5.4            
Cybex [Member]                
Business Acquisition [Line Items]                
Business Acquisition, Percentage of Voting Interests Acquired     100.00%          
Business Combination, Consideration Transferred     $ 196.9          
Unaudited Sales, Business Acquired           $ 169.0    
Accounts and Notes Receivable [1]     21.9          
Inventory [1]     13.9          
Goodwill [1],[2]     86.5          
Property, Plant and Equipment [1]     39.8          
Other Assets [1]     3.7          
Total Assets Acquired [1]     249.3          
Total Liabilities Assumed [1]     52.4          
Net cash consideration paid [1],[3]     196.9          
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Consideration Transferred       $ 1.9 $ 1.9      
Cybex [Member] | Customer Relationships [Member]                
Business Acquisition [Line Items]                
Finite-Lived Intangibles [1]     41.8          
Useful Life         16 years      
Cybex [Member] | Patents and proprietary technology                
Business Acquisition [Line Items]                
Finite-Lived Intangibles [1]     3.1          
Useful Life         5 years      
Cybex [Member] | Trade Names [Member]                
Business Acquisition [Line Items]                
Indefinite-Lived Intangible Assets [1]     $ 38.6          
[1] These amounts are subject to change within the measurement period as the Company finalizes its fair value estimates.
[2] The goodwill recorded for the acquisition of Cybex is not deductible for tax purposes.
[3] Net cash consideration paid includes a purchase price adjustment of $1.9 million in the third quarter of 2016.