XML 100 R77.htm IDEA: XBRL DOCUMENT v3.8.0.1
Equity Method Investments in Affiliates - Aggregate Purchase Price Allocation (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2017
Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]      
Deferred tax liability $ (660.8) $ (467.4)  
Goodwill 2,628.1 2,662.5 $ 2,668.4
Acquired Client Relationships (Net)      
Schedule of Equity Method Investments [Line Items]      
Definite-lived acquired client relationships(1) 501.9 421.0 621.4
Indefinite-lived acquired client relationships 995.5 $ 1,028.7 $ 1,065.0
2016 New Seven Equity Method Investments | Equity Method Investee      
Schedule of Equity Method Investments [Line Items]      
Tangible assets 2.0    
Deferred tax liability (91.8)    
Goodwill 854.4    
Consideration paid 1,362.3    
2016 New Seven Equity Method Investments | Equity Method Investee | Acquired Client Relationships (Net)      
Schedule of Equity Method Investments [Line Items]      
Definite-lived acquired client relationships(1) [1] 560.8    
Indefinite-lived acquired client relationships $ 36.9    
Expected economic benefit period of acquired client relationship intangibles 15 years    
[1] The expected period of economic benefit utilized in the purchase price allocation for these definite-lived acquired client relationships was 15 years.