v3.5.0.2
Acquisitions (Narrative) (Details) - USD ($)
$ in Millions
6 Months Ended 12 Months Ended
Dec. 14, 2015
Dec. 11, 2015
Jun. 30, 2016
Dec. 31, 2015
Business Acquisition [Line Items]        
Goodwill acquired     $ 12,046.0 $ 12,079.0
Interactive Data Holdings Corporation Acquisition [Member]        
Business Acquisition [Line Items]        
Net assets acquired $ 268.0      
Goodwill acquired 3,247.0      
Business Combination, Consideration Transferred 6,000.0      
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable $ 6.5      
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Consideration Transferred     28.0  
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Liabilities     20.0  
Goodwill, Purchase Accounting Adjustments     47.0  
Business Acquisition, Percentage of Voting Interests Acquired 100.00%      
TRAYPORT [Member]        
Business Acquisition [Line Items]        
Net assets acquired   $ 8.0    
Goodwill acquired   388.0    
Business Combination, Consideration Transferred   620.0    
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable   $ 2.5    
Business Acquisition, Percentage of Voting Interests Acquired   100.00%    
Data/Databases [Member] | Interactive Data Holdings Corporation Acquisition [Member]        
Business Acquisition [Line Items]        
Finite-Lived Intangible Assets, Purchase Accounting Adjustments     33.0  
Trademarks and Trade Names [Member] | Interactive Data Holdings Corporation Acquisition [Member]        
Business Acquisition [Line Items]        
Finite-Lived Intangible Assets, Purchase Accounting Adjustments     21.0  
Customer Relationships [Member] | Interactive Data Holdings Corporation Acquisition [Member]        
Business Acquisition [Line Items]        
Finite-Lived Intangible Assets, Purchase Accounting Adjustments     $ 17.0  
Senior Notes [Member] | Interactive Data Holdings Corporation Acquisition [Member]        
Business Acquisition [Line Items]        
Proceeds from Issuance of Debt $ 2,500.0      
Revolving Credit Facility [Member] | Interactive Data Holdings Corporation Acquisition [Member]        
Business Acquisition [Line Items]        
Proceeds from Lines of Credit $ 1,600.0     $ 1,600.0