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 9 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Aug. 20, 2021
Dec. 31, 2020
Jul. 10, 2020
Net income (loss) $ (15,835) $ (25,471) $ (50,543) $ (286,637)      
Accumulated deficit (774,685)   (774,685)     $ (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 15,000   15,000        
MPX New Jersey LLC [Member]              
Percentage of voting equity interests acquired         100.00%    
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 26,900   26,900        
Unsecured Debt [Member]              
Debt Instrument debt default accrued interest amount $ 8,400   $ 8,400        
Senior secured convertible debentures [Member]              
Debt instrument interest rate     13.00%        
Convertible unsecured debentures [Member]              
Debt instrument interest rate     8.00%