Note 2 - Summary of Significant Accounting Policies - Summary of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) |
Aug. 31, 2020 |
May 31, 2020 |
Nov. 30, 2019 |
Aug. 31, 2019 |
May 31, 2019 |
|---|---|---|---|---|---|
| Cash and cash equivalents | $ 1,076,612 | $ 1,095,235 | $ 1,031,722 | ||
| Restricted cash | 297,469 | 385,655 | |||
| Total cash, cash equivalents and restricted cash | $ 1,374,081 | $ 1,495,669 | $ 1,417,377 | $ 1,509,227 |