Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Summary of the impact by financial statement line item of corrections (Details)

v3.21.4
Summary of Significant Accounting Policies - Summary of the impact by financial statement line item of corrections (Details) - USD ($)
 3 Months Ended 6 Months Ended 9 Months Ended 12 Months Ended
Nov. 30, 2021
Aug. 31, 2021
Feb. 28, 2021
Nov. 30, 2020
Aug. 31, 2020
Nov. 30, 2021
Nov. 30, 2020
Feb. 28, 2021
May 31, 2021
May 31, 2020
May 31, 2019
May 31, 2018
Summary Of Significant Accounting Policies [Line Items]                        
Inducement interest expense $ (4,704,000) $ (528,000) $ (5,360,000) $ (4,217,000)   $ (5,232,000) $ (7,562,000) $ (12,922,000) $ (13,922,000) $ (23,437,000) $ (4,728,000)  
Total interest expense (7,970,000) (3,229,000) (6,797,000) (6,753,000)   (11,199,000) (11,913,000) (18,711,000) (22,112,000) (33,752,000) (7,845,000)  
Loss before income taxes (36,604,000) (31,458,000) (45,206,000) (35,425,000)   (68,062,000) (66,257,000) (111,463,000) (157,230,000) (139,936,000) (63,546,000)  
Income tax benefit           0 0       2,827,000  
Net loss $ (36,604,000) $ (31,458,000) $ (45,206,000) $ (35,425,000) $ (30,832,000) $ (68,062,000) $ (66,257,000) $ (111,463,000) $ (157,230,000) $ (139,936,000) $ (60,719,000)  
Earnings Per Share, Basic   $ (0.05) $ (0.08) $ (0.06)     $ (0.12) $ (0.18) $ (0.27) $ (0.34) $ (0.23)  
Earnings Per Share, Diluted $ (0.06) $ (0.05) $ (0.08) $ (0.06)   $ (0.11) $ (0.12) $ (0.18) $ (0.27) $ (0.34) $ (0.23)  
Additional paid-in capital $ 589,971,000 $ 540,481,000       $ 589,971,000     $ 512,796,000 $ 372,301,000 $ 225,177,000  
Accumulated (deficit) $ (603,353,000) (566,318,000)       $ (603,353,000)     (534,440,000) (375,301,000) (234,420,000)  
Adjustments                   15,533,000 4,532,000 $ 525,000
Previously Reported [Member]                        
Summary Of Significant Accounting Policies [Line Items]                        
Inducement interest expense   (9,000) $ (4,139,000) $ (3,758,000)     $ (7,103,000) $ (11,242,000) (11,366,000) (7,904,000) (196,000)  
Total interest expense   (2,710,000) (5,576,000) (6,294,000)     (11,454,000) (17,031,000) (19,556,000) (18,219,000) (3,313,000)  
Loss before income taxes   (30,939,000) (43,985,000) (34,966,000)     (65,798,000) (109,783,000) (154,674,000) (124,403,000) (59,014,000)  
Income tax benefit                     2,827,000  
Net loss   $ (30,939,000) $ (43,985,000) $ (34,966,000) $ (30,832,000)   $ (65,798,000) $ (109,783,000) $ (154,674,000) $ (124,403,000) $ (56,187,000)  
Earnings Per Share, Basic   $ (0.05) $ (0.08) $ (0.06)       $ (0.18) $ (0.27) $ (0.30) $ (0.21)  
Earnings Per Share, Diluted   $ (0.05) $ (0.08) $ (0.06)     $ (0.12) $ (0.18) $ (0.27) $ (0.30) $ (0.21)  
Additional paid-in capital   $ 516,816,000             $ 489,650,000 $ 351,711,000 $ 220,120,000  
Accumulated (deficit)   (542,653,000)             (511,294,000) (354,711,000) (229,363,000)  
Revision of Prior Period, Adjustment [Member]                        
Summary Of Significant Accounting Policies [Line Items]                        
Inducement interest expense   (519,000) $ (1,221,000) $ (459,000)     $ (459,000) $ (1,680,000) (2,556,000) (15,533,000) (4,532,000)  
Total interest expense   (519,000) (1,221,000) (459,000)     (459,000) (1,680,000) (2,556,000) (15,533,000) (4,532,000)  
Loss before income taxes   (519,000) (1,221,000) (459,000)     (459,000) (1,680,000) (2,556,000) (15,533,000) (4,532,000)  
Net loss   $ (519,000) $ (1,221,000) $ (459,000)     $ (459,000) $ (1,680,000) $ (2,556,000) $ (15,533,000) $ (4,532,000)  
Earnings Per Share, Basic     $ 0.00 $ 0.00     $ 0.00 $ 0.00   $ (0.04) $ (0.02)  
Earnings Per Share, Diluted   $ 0.00             $ 0.00 $ (0.04) $ (0.02)  
Additional paid-in capital   $ 23,665,000             $ 23,146,000 $ 20,590,000 $ 5,057,000  
Accumulated (deficit)   $ (23,665,000)             $ (23,146,000) $ (20,590,000) $ (5,057,000)