| Form type | Document | Filing | Description | Filing date | Reporting date | File number(s) | 
|---|---|---|---|---|---|---|
| 15-12G | Open Document | Open Filing | 15-12G | May 9, 2025 | 000-26200 | |
| 10-Q | Open Document | Data | Open Filing | 10-Q | Feb 12, 2025 | Dec 31, 2024 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | 10-Q | Nov 7, 2024 | Sep 30, 2024 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | 10-Q | Aug 9, 2024 | Jun 30, 2024 | 000-26200 | 
| 10-K | Open Document | Data | Open Filing | 10-K | Jun 21, 2024 | Mar 31, 2024 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | 10-Q | Feb 9, 2024 | Dec 31, 2023 | 000-26200 | 
| 8-K | Open Document | Data | Open Filing | FORM 8-K | Jan 5, 2024 | Dec 29, 2023 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | 10-Q | Nov 9, 2023 | Sep 30, 2023 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | 10-Q | Aug 10, 2023 | Jun 30, 2023 | 000-26200 | 
| 10-K | Open Document | Data | Open Filing | 10-K | Jun 21, 2023 | Mar 31, 2023 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | 10-Q | Feb 13, 2023 | Dec 31, 2022 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | 10-Q | Nov 10, 2022 | Sep 30, 2022 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | 10-Q | Aug 11, 2022 | Jun 30, 2022 | 000-26200 | 
| 10-K | Open Document | Data | Open Filing | 10-K | Jun 24, 2022 | Mar 31, 2022 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | 10-Q | Feb 11, 2022 | Dec 31, 2021 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | 10-Q | Nov 10, 2021 | Sep 30, 2021 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | FORM 10-Q | Aug 12, 2021 | Jun 30, 2021 | 000-26200 | 
| 10-K | Open Document | Data | Open Filing | FORM 10-K | Jun 28, 2021 | Mar 31, 2021 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | FORM 10-Q | Feb 12, 2021 | Dec 31, 2020 | 000-26200 | 
| 8-K | Open Document | Open Filing | FORM 8-K | Dec 16, 2020 | Dec 15, 2020 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | BCTC IV SEPTEMBER 2020 10-Q | Nov 12, 2020 | Sep 30, 2020 | 000-26200 | 
| 8-K | Open Document | Open Filing | FORM 8-K | Sep 14, 2020 | Sep 11, 2020 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | BCTC IV JUNE 2020 10-Q | Aug 12, 2020 | Jun 30, 2020 | 000-26200 | 
| 10-K | Open Document | Data | Open Filing | FORM 10-K | Jun 19, 2020 | Mar 31, 2020 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | BCTC IV DEC 2019 10-Q | Feb 13, 2020 | Dec 31, 2019 | 000-26200 | 
| UPLOAD | Open Document | Open Filing | Feb 12, 2020 | |||
| CORRESP | Open Document | Open Filing | Feb 6, 2020 | |||
| UPLOAD | Open Document | Open Filing | Jan 31, 2020 | |||
| 10-Q | Open Document | Data | Open Filing | BCTC IV SEPT 2019 10-Q | Nov 13, 2019 | Sep 30, 2019 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | BCTC IV JUNE 2019 10-Q | Aug 13, 2019 | Jun 30, 2019 | 000-26200 | 
| 10-K | Open Document | Data | Open Filing | FORM 10-K | Jun 20, 2019 | Mar 31, 2019 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | BCTC IV DECEMBER 2018 10-Q | Feb 13, 2019 | Dec 31, 2018 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | BCTC IV SEPT 2018 10-Q | Nov 13, 2018 | Sep 30, 2018 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | BCTC IV JUNE 2018 10-Q | Aug 13, 2018 | Jun 30, 2018 | 000-26200 | 
| 10-K | Open Document | Data | Open Filing | FORM 10-K | Jun 22, 2018 | Mar 31, 2018 | 000-26200 | 
| 8-K | Open Document | Open Filing | 8-K FILING | May 8, 2018 | May 3, 2018 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | BCTC IV DECEMBER 2017 10-Q | Feb 13, 2018 | Dec 31, 2017 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | BCTC IV SEPT 2017 10-Q | Nov 13, 2017 | Sep 30, 2017 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | BCTC IV JUNE 2017 10-Q | Aug 11, 2017 | Jun 30, 2017 | 000-26200 | 
| 10-K | Open Document | Data | Open Filing | FORM 10-K | Jun 23, 2017 | Mar 31, 2017 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | BCTC IV DECEMBER 2016 10-Q | Feb 13, 2017 | Dec 31, 2016 | 000-26200 | 
| 8-K | Open Document | Open Filing | 8-K FILING | Jan 4, 2017 | Jan 3, 2017 | 000-26200 | 
| DEFA14A | Open Document | Open Filing | DEFA14A FILING | Dec 5, 2016 | 000-26200 | |
| DEFA14A | Open Document | Open Filing | DEFA14A | Nov 14, 2016 | 000-26200 | |
| 10-Q | Open Document | Data | Open Filing | BCTC IV SEPT 2016 10-Q | Nov 14, 2016 | Sep 30, 2016 | 000-26200 | 
| DEF 14A | Open Document | Open Filing | DEF 14A FILING | Sep 21, 2016 | Sep 21, 2017 | 000-26200 | 
| PRE 14A | Open Document | Open Filing | PRE 14A FILING | Sep 2, 2016 | Aug 30, 2016 | 000-26200 | 
| 8-K | Open Document | Open Filing | 8-K FILING | Aug 15, 2016 | Aug 15, 2016 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | BCTC IV JUNE 2016 10-Q | Aug 12, 2016 | Jun 30, 2016 | 000-26200 | 
| 10-K | Open Document | Data | Open Filing | 10-K | Jun 23, 2016 | Mar 31, 2016 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | BCTC IV DECEMBER 2015 10-Q | Feb 12, 2016 | Dec 31, 2015 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | BCTC IV SEPTEMBER 2015 10-Q | Nov 13, 2015 | Sep 30, 2015 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | BCTC IV JUNE 2015 10-Q | Aug 13, 2015 | Jun 30, 2015 | 000-26200 | 
| 10-K | Open Document | Data | Open Filing | 10-K | Jun 25, 2015 | Mar 31, 2015 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | BCTC IV DECEMBER 2014 10-Q | Feb 13, 2015 | Dec 31, 2014 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | BCTC IV SEPTEMBER 2014 10-Q | Nov 14, 2014 | Sep 30, 2014 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | BCTC IV JUNE 2014 10-Q | Aug 14, 2014 | Jun 30, 2014 | 000-26200 | 
| 10-K | Open Document | Data | Open Filing | 10-K | Jul 10, 2014 | Mar 31, 2014 | 000-26200 | 
| NT 10-K | Open Document | Open Filing | BCTC IV 3/31/14 10-K EXTENSION | Jun 30, 2014 | Mar 31, 2014 | 000-26200 | 
| 10-Q | Open Document | Data | Open Filing | BCTC IV DECEMBER 2013 10-Q | Feb 14, 2014 | Dec 31, 2013 | 000-26200 |