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Revenue from Contracts with Clients (Narrative) (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Dec. 31, 2017
Disaggregation of Revenue [Line Items]          
Security commissions and trading income $ 21.9 $ 21.2 $ 75.2 $ 65.8  
Other operating income 20.9   87.1    
Estate settlement revenue transition adjustment         $ 2.7
Securities Commissions and Trading Income          
Disaggregation of Revenue [Line Items]          
Revenue from contract with client 19.7   66.0    
Other Operating Income          
Disaggregation of Revenue [Line Items]          
Revenue from contract with client $ 10.4   $ 33.3