Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0000015847-25-000006-index-headers.html | 2025-09-11 17:32:31 | |
| 0000015847-25-000006-index.html | 2025-09-11 17:32:31 | |
| 0000015847-25-000006.txt | 2025-09-11 17:32:31 | |
 0000015847-25-000006-xbrl.zip | 175467 | 2025-09-11 17:32:31 |
| buks-20250731.htm | 849662 | 2025-09-11 17:32:31 |
| buks-20250731.xsd | 42509 | 2025-09-11 17:32:31 |
| buks-20250731xexx311.htm | 9599 | 2025-09-11 17:32:31 |
| buks-20250731xexx312.htm | 9607 | 2025-09-11 17:32:31 |
| buks-20250731xexx321.htm | 5099 | 2025-09-11 17:32:31 |
| buks-20250731xexx322.htm | 5102 | 2025-09-11 17:32:31 |
| buks-20250731_cal.xml | 57103 | 2025-09-11 17:32:31 |
| buks-20250731_def.xml | 145203 | 2025-09-11 17:32:31 |
| buks-20250731_htm.xml | 654304 | 2025-09-11 17:32:31 |
| buks-20250731_lab.xml | 529657 | 2025-09-11 17:32:31 |
| buks-20250731_pre.xml | 353853 | 2025-09-11 17:32:31 |
| FilingSummary.xml | 34546 | 2025-09-11 17:32:31 |
| MetaLinks.json | 786171 | 2025-09-11 17:32:31 |
| R1.htm | 48301 | 2025-09-11 17:32:31 |
| R10.htm | 17584 | 2025-09-11 17:32:31 |
| R11.htm | 66575 | 2025-09-11 17:32:31 |
| R12.htm | 11322 | 2025-09-11 17:32:31 |
| R13.htm | 11868 | 2025-09-11 17:32:31 |
| R14.htm | 22536 | 2025-09-11 17:32:31 |
| R15.htm | 4613 | 2025-09-11 17:32:31 |
| R16.htm | 5974 | 2025-09-11 17:32:31 |
| R17.htm | 15532 | 2025-09-11 17:32:31 |
| R18.htm | 6205 | 2025-09-11 17:32:31 |
| R19.htm | 19583 | 2025-09-11 17:32:31 |
| R2.htm | 134530 | 2025-09-11 17:32:31 |
| R20.htm | 27450 | 2025-09-11 17:32:31 |
| R21.htm | 24997 | 2025-09-11 17:32:31 |
| R22.htm | 54059 | 2025-09-11 17:32:31 |
| R23.htm | 5132 | 2025-09-11 17:32:31 |
| R24.htm | 21286 | 2025-09-11 17:32:31 |
| R25.htm | 15118 | 2025-09-11 17:32:31 |
| R26.htm | 66946 | 2025-09-11 17:32:31 |
| R27.htm | 9374 | 2025-09-11 17:32:31 |
| R28.htm | 11981 | 2025-09-11 17:32:31 |
| R29.htm | 21904 | 2025-09-11 17:32:31 |
| R3.htm | 29342 | 2025-09-11 17:32:31 |
| R30.htm | 14487 | 2025-09-11 17:32:31 |
| R31.htm | 26388 | 2025-09-11 17:32:31 |
| R32.htm | 28438 | 2025-09-11 17:32:31 |
| R33.htm | 45438 | 2025-09-11 17:32:31 |
| R34.htm | 4024 | 2025-09-11 17:32:31 |
| R35.htm | 13503 | 2025-09-11 17:32:31 |
| R36.htm | 68208 | 2025-09-11 17:32:31 |
| R37.htm | 10988 | 2025-09-11 17:32:31 |
| R38.htm | 16201 | 2025-09-11 17:32:31 |
| R39.htm | 4010 | 2025-09-11 17:32:31 |
| R4.htm | 87883 | 2025-09-11 17:32:31 |
| R40.htm | 13978 | 2025-09-11 17:32:31 |
| R41.htm | 23731 | 2025-09-11 17:32:31 |
| R42.htm | 5986 | 2025-09-11 17:32:31 |
| R43.htm | 11833 | 2025-09-11 17:32:31 |
| R44.htm | 5957 | 2025-09-11 17:32:31 |
| R45.htm | 59857 | 2025-09-11 17:32:31 |
| R46.htm | 23738 | 2025-09-11 17:32:31 |
| R47.htm | 53918 | 2025-09-11 17:32:31 |
| R48.htm | 22365 | 2025-09-11 17:32:31 |
| R49.htm | 17190 | 2025-09-11 17:32:31 |
| R5.htm | 57123 | 2025-09-11 17:32:31 |
| R50.htm | 15507 | 2025-09-11 17:32:31 |
| R51.htm | 10262 | 2025-09-11 17:32:31 |
| R52.htm | 8367 | 2025-09-11 17:32:31 |
| R53.htm | 27967 | 2025-09-11 17:32:31 |
| R54.htm | 13715 | 2025-09-11 17:32:31 |
| R55.htm | 23853 | 2025-09-11 17:32:31 |
| R56.htm | 32269 | 2025-09-11 17:32:31 |
| R57.htm | 13690 | 2025-09-11 17:32:31 |
| R6.htm | 84404 | 2025-09-11 17:32:31 |
| R7.htm | 6967 | 2025-09-11 17:32:31 |
| R8.htm | 5387 | 2025-09-11 17:32:31 |
| R9.htm | 5618 | 2025-09-11 17:32:31 |
| report.css | 2767 | 2025-09-11 17:32:31 |
| Show.js | 1085 | 2025-09-11 17:32:31 |