| Form type | Document | Filing | Description | Filing date | Reporting date | File number(s) |
|---|---|---|---|---|---|---|
| 4 | Open Document | Open Filing | FORM 4 SUBMISSION | Dec 16, 2021 | Dec 16, 2021 | 000-55428 |
| 4 | Open Document | Open Filing | FORM 4 | Mar 16, 2021 | Mar 15, 2021 | 000-55428 |
| 4 | Open Document | Open Filing | PRIMARY DOCUMENT | Sep 2, 2020 | Sep 1, 2020 | 000-55428 |
| 3 | Open Document | Open Filing | PRIMARY DOCUMENT | Sep 2, 2020 | Sep 1, 2020 | 000-55428 |
| 4 | Open Document | Open Filing | OWNERSHIP DOCUMENT | Sep 5, 2017 | Aug 31, 2017 | 811-23210 |
| 3 | Open Document | Open Filing | OWNERSHIP DOCUMENT | May 8, 2017 | May 8, 2017 | 811-23210 |