XML 66 R49.htm IDEA: XBRL DOCUMENT v3.6.0.2
Description of Business and Summary of Significant Accounting Policies (Revenue Recognition, Advertising) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Advertising [Abstract]        
Advertising expense, net $ 196.7 $ 188.5 $ 164.9  
Manufacturer advertising reimbursements 58.5 56.4 47.1  
Chargeback Reserves [Member]        
Revenue Recognition [Abstract]        
Chargeback liabilities $ 116.8 $ 97.3 $ 84.9 $ 67.6