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Fair Value Measurements - Additional Information (Detail)
£ in Millions, $ in Millions, $ in Millions
3 Months Ended
Mar. 31, 2020
USD ($)
Mar. 31, 2020
GBP (£)
Mar. 31, 2020
CAD ($)
Mar. 31, 2019
USD ($)
Derivative [Line Items]        
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount $ 0.0     $ 0.0
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount 0.0     $ 0.0
Foreign Exchange Forward [Member] | Canada, Dollars        
Derivative [Line Items]        
Derivative, notional amount     $ 24  
Fair value unrealized gain (0.5)      
Foreign Exchange Forward [Member] | United Kingdom, Pounds        
Derivative [Line Items]        
Derivative, notional amount | £   £ 10    
Fair value unrealized gain $ 1.0