XML 59 R43.htm IDEA: XBRL DOCUMENT v3.8.0.1
Summary of Significant Accounting Policies - Investments in Unconsolidated Variable Interest Entities (Details) - USD ($)
$ in Millions
Sep. 30, 2017
Dec. 31, 2016
Variable Interest Entity [Line Items]    
Investments $ 1,480.9 $ 1,107.0
Variable Interest Entity, Primary Beneficiary    
Variable Interest Entity [Line Items]    
Investments 828.5 664.2
Due from affiliates, net 0.0 1.8
Maximum Exposure to Loss 828.5 $ 666.0
Amount of variable interests in unconsolidated VIEs related to performance fees 51.9  
Amount of variable interests in unconsolidated VIEs related to management fees $ 12.8