XML 111 R77.htm IDEA: XBRL DOCUMENT v3.20.4
Income Taxes - Additional Information (Detail) - USD ($)
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Valuation Allowance [Line Items]        
Increase in valuation allowance $ 70,700,000      
Non-US Net operating loss carryforwards $ 1,416,700,000      
Operating loss carryforwards expiration period 2023      
Unrecognized tax benefits, gross $ 11,967,000 $ 5,231,000 $ 1,595,000 $ 354,000
Unrecognized tax benefits would favorably impact the effective tax rate if recognized 11,000,000.0      
Accrued interest or penalties related to uncertain tax positions 0 0 0  
Uncertain tax positions recognized 0 $ 0 $ 0  
U.S. Domestic Federal [Member] | Research and Development [Member]        
Valuation Allowance [Line Items]        
Tax credit carryforward amount $ 13,900,000      
Tax credit carryforward, expiration year 2040      
Uncertain tax positions $ 7,500,000      
U.S. Domestic State [Member] | Research and Development [Member]        
Valuation Allowance [Line Items]        
Tax credit carryforward amount $ 6,900,000      
Tax credit carryforward, expiration year 2034      
Uncertain tax positions $ 4,500,000      
Switzerland [Member]        
Valuation Allowance [Line Items]        
Non-US Net operating loss carryforwards 707,600,000      
Canton of Zug [Member]        
Valuation Allowance [Line Items]        
Non-US Net operating loss carryforwards 707,600,000      
UNITED KINGDOM [Member]        
Valuation Allowance [Line Items]        
Non-US Net operating loss carryforwards $ 1,500,000