v3.8.0.1
Financial Statement Details Financial Statement Details - Property and Equipment (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Property, Plant and Equipment [Line Items]      
Property and Equipment, Gross $ 200.4 $ 156.6  
Accumulated depreciation (54.8) (47.2)  
Property and equipment, net 145.6 109.4  
Depreciation 16.1 14.4 $ 10.2
Building (1)      
Property, Plant and Equipment [Line Items]      
Property and Equipment, Gross 6.0 6.0  
Furniture and fixtures      
Property, Plant and Equipment [Line Items]      
Property and Equipment, Gross 5.7 5.8  
Computer equipment      
Property, Plant and Equipment [Line Items]      
Property and Equipment, Gross 25.6 22.7  
Machinery and equipment      
Property, Plant and Equipment [Line Items]      
Property and Equipment, Gross 33.8 31.4  
Leasehold improvements      
Property, Plant and Equipment [Line Items]      
Property and Equipment, Gross 41.7 25.6  
Construction in progress (2)      
Property, Plant and Equipment [Line Items]      
Property and Equipment, Gross 87.6 65.1  
Property, Plant and Equipment, Disposals 9.2    
Leased Buildings -232 South Dobson Road [Member]      
Property, Plant and Equipment [Line Items]      
Construction in Progress, Gross $ 33.6 $ 24.8