Quarterly report pursuant to Section 13 or 15(d)

Overview and Basis of Presentation - Additional Information (Detail)

v3.21.2
Overview and Basis of Presentation - Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Dec. 31, 2020
Jul. 10, 2020
Net income (loss) $ (15,256) $ (24,825) $ (34,708) $ (261,166)    
Accumulated deficit (758,850)   (758,850)   $ (724,142)  
Debt instrument debt default amount 97,500   97,500      
Debt instrument debt default principal amount 60,000   60,000      
Debt instrument debt default accrued additional fees and interest 14,600   14,600      
Revenue [Member]            
Increase in cost and expenses     2,900      
Recapitalization transaction [Member]            
Debt instrument face amount           $ 14,700
Secured Debt [Member]            
Debt Instrument debt default accrued interest amount 22,900   22,900      
Unsecured Debt [Member]            
Debt Instrument debt default accrued interest amount $ 7,200   $ 7,200      
Senior secured convertible debentures [Member]            
Debt instrument interest rate     13.00%      
Convertible unsecured debentures [Member]            
Debt instrument interest rate     8.00%