| Form type | Document | Filing | Description | Filing date | Reporting date | File number(s) |
|---|---|---|---|---|---|---|
| 4 | Open Document | Open Filing | OWNERSHIP DOCUMENT | Nov 2, 2021 | Nov 1, 2021 | 000-55882 |
| 4 | Open Document | Open Filing | OWNERSHIP DOCUMENT | Oct 5, 2021 | Oct 5, 2021 | 000-55882 |
| 4 | Open Document | Open Filing | OWNERSHIP DOCUMENT | Feb 3, 2021 | Feb 1, 2021 | 000-55882 |
| 4 | Open Document | Open Filing | Dec 9, 2019 | Dec 5, 2019 | 000-55882 | |
| 4 | Open Document | Open Filing | OWNERSHIP DOCUMENT | Nov 26, 2019 | Nov 25, 2019 | 000-55882 |
| SC 13D/A | Open Document | Open Filing | AMENDMENT NO. 2 TO SC 13D | Sep 9, 2019 | ||
| 4 | Open Document | Open Filing | Sep 5, 2019 | Sep 3, 2019 | 000-55882 | |
| SC 13D/A | Open Document | Open Filing | SCHEDULE 13D | Feb 1, 2019 | ||
| 4 | Open Document | Open Filing | Jan 31, 2019 | Jan 29, 2019 | 000-55882 | |
| SC 13D | Open Document | Open Filing | SCHEDULE 13D | Oct 5, 2018 | ||
| 3 | Open Document | Open Filing | Oct 5, 2018 | Sep 25, 2018 | 000-55882 | |
| 4 | Open Document | Open Filing | OWNERSHIP DOCUMENT | Jun 19, 2017 | Jun 16, 2017 | 001-38113 |
| 3 | Open Document | Open Filing | OWNERSHIP DOCUMENT | Nov 9, 2016 | Nov 9, 2016 | 000-55714 |