Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation??and Summary of Significant Accounting Policies - Narrative (Details)

v3.21.4
Basis of Presentation and Summary of Significant Accounting Policies - Narrative (Details)
1 Months Ended 2 Months Ended 3 Months Ended 8 Months Ended 9 Months Ended 12 Months Ended
Jun. 10, 2021
USD ($)
Sep. 30, 2021
USD ($)
Sep. 14, 2021
USD ($)
Sep. 30, 2021
USD ($)
segment
Sep. 30, 2020
USD ($)
segment
Sep. 14, 2021
USD ($)
plan
Sep. 30, 2021
USD ($)
segment
landfill
Sep. 30, 2020
USD ($)
segment
Dec. 31, 2020
USD ($)
Sep. 30, 2017
USD ($)
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]                    
Accounts payable - trade   $ 6,466,000   $ 6,466,000     $ 6,466,000   $ 14,845,000  
General and administrative expenses       11,889,000 $ 1,205,000   22,933,000 $ 3,652,000    
Net income (loss)   (7,067,000) $ (8,848,000) $ (24,177,000) $ (602,000) $ (19,278,000) $ (34,606,000) $ (1,819,000)    
Percent of revenue, ASC 606             82.00% 100.00%    
Percent of revenue, ASC 840             18.00%      
Number of operating landfill gas to electricity facilities | landfill             12      
Reporting segment | segment       2 2   2 2    
Adjustment                    
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]                    
Accounts payable - trade   $ 2,836,000   $ 2,836,000     $ 2,836,000      
General and administrative expenses       2,836,000     2,836,000      
Net income (loss)       (2,836,000)     (2,836,000)      
Mavrix                    
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]                    
Net income (loss)       $ 1,130,000     1,130,000      
Earn-out payment             $ 1,700,000      
Mavrix | Maximum                    
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]                    
Earn-out payment obligation                   $ 9,550,000
Aria Energy LLC                    
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]                    
Accounts payable - trade                 1,570,000  
General and administrative expenses     20,678,000   $ 5,303,000 33,737,000   $ 14,934,000    
Net income (loss)     (534,000)   532,000 $ 84,520,000   $ (6,071,000)    
Percent of revenue, ASC 606           36.00%   42.00%    
Percent of revenue, ASC 840           64.00%   58.00%    
Reporting segment | plan           2        
Proceeds from sale of assets held for sale $ 58,500,000                  
Gain on extinguishment of debt 61,400,000   0   0 $ 61,411,000   $ 0    
Gain on sale of assets $ 1,300,000                  
Net gain (loss) from sale of LESPH           67,300,000   (9,500,000)    
Aria Energy LLC | LESPH                    
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]                    
Net gain (loss) from sale of LESPH           67,600,000   (9,600,000)    
Aria Energy LLC | Mavrix                    
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]                    
Net income (loss)     6,451,000   $ 2,558,000 19,777,000   $ 6,005,000    
Earn-out payment           1,700,000     1,400,000  
Earn-out payment obligation     1,700,000     1,700,000     $ 1,400,000  
Aria Energy LLC | Mavrix | Maximum                    
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]                    
Earn-out payment obligation     $ 9,550,000     $ 9,550,000        
3.75% Term Note | Senior notes                    
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]                    
Debt instrument, interest rate   3.75%   3.75%     3.75%      
4.47% Term Note | Senior notes                    
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]                    
Debt instrument, interest rate   4.47%   4.47%     4.47%