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Description of the Business and Summary of Significant Accounting Policies - Revenue Recognition (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]    
Revenue, performance obligation, description of timing one year or longer  
Revenue recognized $ 222.6 $ 188.2
Remaining performance obligation $ 549.8  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]    
Performance obligation satisfaction period 12 months