v3.20.2
Commitments and Contingencies - Additional Information (Detail) - USD ($)
$ in Millions
1 Months Ended 3 Months Ended 9 Months Ended 12 Months Ended
Jun. 30, 2020
Dec. 31, 2019
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
Dec. 31, 2019
Loss Contingencies [Line Items]              
Net rent expense     $ 8.3 $ 10.4 $ 26.8 $ 26.0  
Sublease income     4.5 $ 3.7 13.9 $ 10.5  
Letter of credit outstanding amount   $ 322.8 130.1   $ 130.1   $ 322.8
Letters of credit and guarantees [Member]              
Loss Contingencies [Line Items]              
Line of credit termination date         Aug. 31, 2028   Aug. 31, 2028
Purchase Commitment One [Member]              
Loss Contingencies [Line Items]              
Minimum annual commitment   $ 1,490.0          
Long-term Purchase Commitment, Description   If the difference is greater than $30.0 million for each of the first three contract years or $50.0 million for each of the contract years thereafter (“relief amounts”), the Company has the option to pay the respective relief amount for that year for services to be utilized in the future and the excess amount of the difference above the relief amount would be added to the minimum annual commitment of the following year through the end of the contract.          
Satisfied purchase commitment         $ 60.0    
Purchase Commitment One [Member] | Relief Amount For Future Cloud Hosting Services Member [Member]              
Loss Contingencies [Line Items]              
Relief amount payable in the future     $ 30.0   30.0    
Purchase Commitment Two [Member]              
Loss Contingencies [Line Items]              
Minimum annual commitment $ 45.0            
Satisfied purchase commitment $ 1.6       $ 126.0