Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0000950170-24-011023-index-headers.html | 2024-02-05 08:30:35 | |
| 0000950170-24-011023-index.html | 2024-02-05 08:30:35 | |
| 0000950170-24-011023.txt | 2024-02-05 08:30:35 | |
 0000950170-24-011023-xbrl.zip | 411921 | 2024-02-05 08:30:35 |
| FilingSummary.xml | 37788 | 2024-02-05 08:30:35 |
| Financial_Report.xlsx | 84876 | 2024-02-05 08:30:35 |
| ghm-20231231.htm | 2023643 | 2024-02-05 08:30:35 |
| ghm-20231231.xsd | 1426652 | 2024-02-05 08:30:35 |
| ghm-20231231_htm.xml | 1674362 | 2024-02-05 08:30:35 |
| ghm-ex31_1.htm | 12501 | 2024-02-05 08:30:35 |
| ghm-ex31_2.htm | 12000 | 2024-02-05 08:30:35 |
| ghm-ex32_1.htm | 8140 | 2024-02-05 08:30:35 |
 img101497535_0.jpg | 62712 | 2024-02-05 08:30:35 |
 img101497535_1.jpg | 105041 | 2024-02-05 08:30:35 |
 img101497535_2.jpg | 70885 | 2024-02-05 08:30:35 |
| MetaLinks.json | 940159 | 2024-02-05 08:30:35 |
| R1.htm | 51547 | 2024-02-05 08:30:35 |
| R10.htm | 73567 | 2024-02-05 08:30:35 |
| R11.htm | 148783 | 2024-02-05 08:30:35 |
| R12.htm | 19959 | 2024-02-05 08:30:35 |
| R13.htm | 62989 | 2024-02-05 08:30:35 |
| R14.htm | 81489 | 2024-02-05 08:30:35 |
| R15.htm | 75954 | 2024-02-05 08:30:35 |
| R16.htm | 34032 | 2024-02-05 08:30:35 |
| R17.htm | 19798 | 2024-02-05 08:30:35 |
| R18.htm | 12980 | 2024-02-05 08:30:35 |
| R19.htm | 11316 | 2024-02-05 08:30:35 |
| R2.htm | 78359 | 2024-02-05 08:30:35 |
| R20.htm | 99814 | 2024-02-05 08:30:35 |
| R21.htm | 35530 | 2024-02-05 08:30:35 |
| R22.htm | 66567 | 2024-02-05 08:30:35 |
| R23.htm | 231379 | 2024-02-05 08:30:35 |
| R24.htm | 20140 | 2024-02-05 08:30:35 |
| R25.htm | 62336 | 2024-02-05 08:30:35 |
| R26.htm | 78649 | 2024-02-05 08:30:35 |
| R27.htm | 74616 | 2024-02-05 08:30:35 |
| R28.htm | 31866 | 2024-02-05 08:30:35 |
| R29.htm | 17603 | 2024-02-05 08:30:35 |
| R3.htm | 28756 | 2024-02-05 08:30:35 |
| R30.htm | 99512 | 2024-02-05 08:30:35 |
| R31.htm | 14064 | 2024-02-05 08:30:35 |
| R32.htm | 9697 | 2024-02-05 08:30:35 |
| R33.htm | 52245 | 2024-02-05 08:30:35 |
| R34.htm | 48440 | 2024-02-05 08:30:35 |
| R35.htm | 13605 | 2024-02-05 08:30:35 |
| R36.htm | 34418 | 2024-02-05 08:30:35 |
| R37.htm | 6729 | 2024-02-05 08:30:35 |
| R38.htm | 9820 | 2024-02-05 08:30:35 |
| R39.htm | 24291 | 2024-02-05 08:30:35 |
| R4.htm | 5525 | 2024-02-05 08:30:35 |
| R40.htm | 13677 | 2024-02-05 08:30:35 |
| R41.htm | 10612 | 2024-02-05 08:30:35 |
| R42.htm | 37987 | 2024-02-05 08:30:35 |
| R43.htm | 17375 | 2024-02-05 08:30:35 |
| R44.htm | 5532 | 2024-02-05 08:30:35 |
| R45.htm | 38139 | 2024-02-05 08:30:35 |
| R46.htm | 21978 | 2024-02-05 08:30:35 |
| R47.htm | 35781 | 2024-02-05 08:30:35 |
| R48.htm | 41905 | 2024-02-05 08:30:35 |
| R49.htm | 9897 | 2024-02-05 08:30:35 |
| R5.htm | 139546 | 2024-02-05 08:30:35 |
| R50.htm | 12295 | 2024-02-05 08:30:35 |
| R51.htm | 7150 | 2024-02-05 08:30:35 |
| R52.htm | 15692 | 2024-02-05 08:30:35 |
| R53.htm | 21019 | 2024-02-05 08:30:35 |
| R54.htm | 30233 | 2024-02-05 08:30:35 |
| R55.htm | 33252 | 2024-02-05 08:30:35 |
| R56.htm | 8349 | 2024-02-05 08:30:35 |
| R57.htm | 83749 | 2024-02-05 08:30:35 |
| R58.htm | 21210 | 2024-02-05 08:30:35 |
| R6.htm | 20871 | 2024-02-05 08:30:35 |
| R7.htm | 98607 | 2024-02-05 08:30:35 |
| R8.htm | 65020 | 2024-02-05 08:30:35 |
| R9.htm | 7836 | 2024-02-05 08:30:35 |
| report.css | 2767 | 2024-02-05 08:30:35 |
| Show.js | 1085 | 2024-02-05 08:30:35 |