Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0001564590-21-004173-index-headers.html | 2021-02-04 06:21:29 | |
| 0001564590-21-004173-index.html | 2021-02-04 06:21:29 | |
| 0001564590-21-004173.txt | 2021-02-04 06:21:29 | |
 0001564590-21-004173-xbrl.zip | 165835 | 2021-02-04 06:21:29 |
| bv-10q_20201231.htm | 2036370 | 2021-02-04 06:21:29 |
| bv-10q_20201231_htm.xml | 1534370 | 2021-02-04 06:21:29 |
| bv-20201231.xsd | 45471 | 2021-02-04 06:21:29 |
| bv-20201231_cal.xml | 53125 | 2021-02-04 06:21:29 |
| bv-20201231_def.xml | 151869 | 2021-02-04 06:21:29 |
| bv-20201231_lab.xml | 347535 | 2021-02-04 06:21:29 |
| bv-20201231_pre.xml | 285484 | 2021-02-04 06:21:29 |
| bv-ex101_8.htm | 129475 | 2021-02-04 06:21:29 |
| bv-ex311_34.htm | 21541 | 2021-02-04 06:21:29 |
| bv-ex312_33.htm | 21577 | 2021-02-04 06:21:29 |
| bv-ex321_31.htm | 9675 | 2021-02-04 06:21:29 |
| bv-ex322_32.htm | 9692 | 2021-02-04 06:21:29 |
| FilingSummary.xml | 36294 | 2021-02-04 06:21:29 |
| Financial_Report.xlsx | 75382 | 2021-02-04 06:21:29 |
| MetaLinks.json | 547925 | 2021-02-04 06:21:29 |
| R1.htm | 53764 | 2021-02-04 06:21:29 |
| R10.htm | 17837 | 2021-02-04 06:21:29 |
| R11.htm | 61147 | 2021-02-04 06:21:29 |
| R12.htm | 5089 | 2021-02-04 06:21:29 |
| R13.htm | 51351 | 2021-02-04 06:21:29 |
| R14.htm | 88490 | 2021-02-04 06:21:29 |
| R15.htm | 60320 | 2021-02-04 06:21:29 |
| R16.htm | 193702 | 2021-02-04 06:21:29 |
| R17.htm | 23384 | 2021-02-04 06:21:29 |
| R18.htm | 16863 | 2021-02-04 06:21:29 |
| R19.htm | 14303 | 2021-02-04 06:21:29 |
| R2.htm | 90327 | 2021-02-04 06:21:29 |
| R20.htm | 111598 | 2021-02-04 06:21:29 |
| R21.htm | 39818 | 2021-02-04 06:21:29 |
| R22.htm | 11206 | 2021-02-04 06:21:29 |
| R23.htm | 48417 | 2021-02-04 06:21:29 |
| R24.htm | 49964 | 2021-02-04 06:21:29 |
| R25.htm | 87823 | 2021-02-04 06:21:29 |
| R26.htm | 59156 | 2021-02-04 06:21:29 |
| R27.htm | 184394 | 2021-02-04 06:21:29 |
| R28.htm | 21153 | 2021-02-04 06:21:29 |
| R29.htm | 13927 | 2021-02-04 06:21:29 |
| R3.htm | 21213 | 2021-02-04 06:21:29 |
| R30.htm | 105492 | 2021-02-04 06:21:29 |
| R31.htm | 38379 | 2021-02-04 06:21:29 |
| R32.htm | 4393 | 2021-02-04 06:21:29 |
| R33.htm | 15708 | 2021-02-04 06:21:29 |
| R34.htm | 19107 | 2021-02-04 06:21:29 |
| R35.htm | 10701 | 2021-02-04 06:21:29 |
| R36.htm | 8531 | 2021-02-04 06:21:29 |
| R37.htm | 10387 | 2021-02-04 06:21:29 |
| R38.htm | 34814 | 2021-02-04 06:21:29 |
| R39.htm | 4823 | 2021-02-04 06:21:29 |
| R4.htm | 48461 | 2021-02-04 06:21:29 |
| R40.htm | 21297 | 2021-02-04 06:21:29 |
| R41.htm | 22996 | 2021-02-04 06:21:29 |
| R42.htm | 16792 | 2021-02-04 06:21:29 |
| R43.htm | 19574 | 2021-02-04 06:21:29 |
| R44.htm | 68545 | 2021-02-04 06:21:29 |
| R45.htm | 25549 | 2021-02-04 06:21:29 |
| R46.htm | 17191 | 2021-02-04 06:21:29 |
| R47.htm | 39559 | 2021-02-04 06:21:29 |
| R48.htm | 17745 | 2021-02-04 06:21:29 |
| R49.htm | 13337 | 2021-02-04 06:21:29 |
| R5.htm | 23609 | 2021-02-04 06:21:29 |
| R50.htm | 39156 | 2021-02-04 06:21:29 |
| R51.htm | 4559 | 2021-02-04 06:21:29 |
| R52.htm | 18521 | 2021-02-04 06:21:29 |
| R53.htm | 4837 | 2021-02-04 06:21:29 |
| R54.htm | 55834 | 2021-02-04 06:21:29 |
| R55.htm | 17588 | 2021-02-04 06:21:29 |
| R6.htm | 7507 | 2021-02-04 06:21:29 |
| R7.htm | 36260 | 2021-02-04 06:21:29 |
| R8.htm | 76845 | 2021-02-04 06:21:29 |
| R9.htm | 10053 | 2021-02-04 06:21:29 |
| report.css | 2767 | 2021-02-04 06:21:29 |
| Show.js | 1085 | 2021-02-04 06:21:29 |