Annual report pursuant to Section 13 and 15(d)

Income Taxes - Additional Information (Detail)

v3.20.4
Income Taxes - Additional Information (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Income Taxes [Line Items]        
Increase in valuation allowance tax $ 82,100 $ 78,100    
Net operating loss carryforwards, federal 811,700      
Net operating loss carryforwards, state 988,100      
Research and development tax credit carryforwards $ 75,100      
Research and development tax credit carryforwards, expiration year 2035      
Unrecognized tax benefits $ 110,601 $ 86,000 $ 41,074 $ 30,051
Unrecognized tax benefits if recognized would impact effective tax rate 0      
Domestic        
Income Taxes [Line Items]        
Net operating loss carryforwards subject to expiration $ 65,300      
Net tax operating losses, expiration begin to expire in 2032      
Net operating loss carryforwards not subject to expiration $ 746,400      
Research and development tax credit carryforwards $ 12,900      
Research and development tax credit carryforwards, expiration year 2032      
State        
Income Taxes [Line Items]        
Net operating loss carryforwards subject to expiration $ 986,400      
Net tax operating losses, expiration begin to expire in 2030      
Research and development tax credit carryforwards $ 21,600