Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0000352825-25-000055-index-headers.html | 2025-03-07 13:30:08 | |
| 0000352825-25-000055-index.html | 2025-03-07 13:30:08 | |
| 0000352825-25-000055.txt | 2025-03-07 13:30:08 | |
 0000352825-25-000055-xbrl.zip | 475799 | 2025-03-07 13:30:08 |
| a202410-kexx1030.htm | 45623 | 2025-03-07 13:30:08 |
| a202410-kexx191.htm | 55905 | 2025-03-07 13:30:08 |
| a202410kex-21.htm | 10743 | 2025-03-07 13:30:08 |
| a202410kex-23.htm | 7554 | 2025-03-07 13:30:08 |
| a202410kex-311.htm | 11722 | 2025-03-07 13:30:08 |
| a202410kex-312.htm | 11897 | 2025-03-07 13:30:08 |
| a202410kex-320.htm | 7720 | 2025-03-07 13:30:08 |
| a202410kex-41.htm | 20348 | 2025-03-07 13:30:08 |
| a202410kex-97.htm | 31825 | 2025-03-07 13:30:08 |
| FilingSummary.xml | 69429 | 2025-03-07 13:30:08 |
| Financial_Report.xlsx | 178985 | 2025-03-07 13:30:08 |
| fstr-20241231.htm | 2127477 | 2025-03-07 13:30:08 |
| fstr-20241231.xsd | 80874 | 2025-03-07 13:30:08 |
| fstr-20241231_cal.xml | 158451 | 2025-03-07 13:30:08 |
| fstr-20241231_def.xml | 440732 | 2025-03-07 13:30:08 |
 fstr-20241231_g1.gif | 40353 | 2025-03-07 13:30:08 |
| fstr-20241231_htm.xml | 2176240 | 2025-03-07 13:30:08 |
| fstr-20241231_lab.xml | 1046800 | 2025-03-07 13:30:08 |
| fstr-20241231_pre.xml | 813114 | 2025-03-07 13:30:08 |
| MetaLinks.json | 1410240 | 2025-03-07 13:30:08 |
| R1.htm | 69123 | 2025-03-07 13:30:08 |
| R10.htm | 9984 | 2025-03-07 13:30:08 |
| R100.htm | 19268 | 2025-03-07 13:30:08 |
| R101.htm | 70888 | 2025-03-07 13:30:08 |
| R102.htm | 26852 | 2025-03-07 13:30:08 |
| R103.htm | 10989 | 2025-03-07 13:30:08 |
| R104.htm | 15579 | 2025-03-07 13:30:08 |
| R105.htm | 30289 | 2025-03-07 13:30:08 |
| R106.htm | 29588 | 2025-03-07 13:30:08 |
| R107.htm | 10859 | 2025-03-07 13:30:08 |
| R108.htm | 9095 | 2025-03-07 13:30:08 |
| R109.htm | 44779 | 2025-03-07 13:30:08 |
| R11.htm | 32524 | 2025-03-07 13:30:08 |
| R110.htm | 12697 | 2025-03-07 13:30:08 |
| R111.htm | 24561 | 2025-03-07 13:30:08 |
| R112.htm | 14024 | 2025-03-07 13:30:08 |
| R113.htm | 14087 | 2025-03-07 13:30:08 |
| R114.htm | 10179 | 2025-03-07 13:30:08 |
| R115.htm | 7404 | 2025-03-07 13:30:08 |
| R116.htm | 13829 | 2025-03-07 13:30:08 |
| R12.htm | 143070 | 2025-03-07 13:30:08 |
| R13.htm | 56310 | 2025-03-07 13:30:08 |
| R14.htm | 59484 | 2025-03-07 13:30:08 |
| R15.htm | 17630 | 2025-03-07 13:30:08 |
| R16.htm | 12138 | 2025-03-07 13:30:08 |
| R17.htm | 18189 | 2025-03-07 13:30:08 |
| R18.htm | 123177 | 2025-03-07 13:30:08 |
| R19.htm | 29651 | 2025-03-07 13:30:08 |
| R2.htm | 7799 | 2025-03-07 13:30:08 |
| R20.htm | 23677 | 2025-03-07 13:30:08 |
| R21.htm | 13781 | 2025-03-07 13:30:08 |
| R22.htm | 23227 | 2025-03-07 13:30:08 |
| R23.htm | 106364 | 2025-03-07 13:30:08 |
| R24.htm | 43504 | 2025-03-07 13:30:08 |
| R25.htm | 35533 | 2025-03-07 13:30:08 |
| R26.htm | 150346 | 2025-03-07 13:30:08 |
| R27.htm | 26130 | 2025-03-07 13:30:08 |
| R28.htm | 19093 | 2025-03-07 13:30:08 |
| R29.htm | 16739 | 2025-03-07 13:30:08 |
| R3.htm | 124733 | 2025-03-07 13:30:08 |
| R30.htm | 5494 | 2025-03-07 13:30:08 |
| R31.htm | 26792 | 2025-03-07 13:30:08 |
| R32.htm | 14536 | 2025-03-07 13:30:08 |
| R33.htm | 8481 | 2025-03-07 13:30:08 |
| R34.htm | 4387 | 2025-03-07 13:30:08 |
| R35.htm | 52838 | 2025-03-07 13:30:08 |
| R36.htm | 70300 | 2025-03-07 13:30:08 |
| R37.htm | 129677 | 2025-03-07 13:30:08 |
| R38.htm | 47030 | 2025-03-07 13:30:08 |
| R39.htm | 64717 | 2025-03-07 13:30:08 |
| R4.htm | 13957 | 2025-03-07 13:30:08 |
| R40.htm | 18305 | 2025-03-07 13:30:08 |
| R41.htm | 12827 | 2025-03-07 13:30:08 |
| R42.htm | 16789 | 2025-03-07 13:30:08 |
| R43.htm | 78327 | 2025-03-07 13:30:08 |
| R44.htm | 24615 | 2025-03-07 13:30:08 |
| R45.htm | 15248 | 2025-03-07 13:30:08 |
| R46.htm | 12521 | 2025-03-07 13:30:08 |
| R47.htm | 22590 | 2025-03-07 13:30:08 |
| R48.htm | 105328 | 2025-03-07 13:30:08 |
| R49.htm | 32137 | 2025-03-07 13:30:08 |
| R5.htm | 96628 | 2025-03-07 13:30:08 |
| R50.htm | 25338 | 2025-03-07 13:30:08 |
| R51.htm | 149064 | 2025-03-07 13:30:08 |
| R52.htm | 17870 | 2025-03-07 13:30:08 |
| R53.htm | 18452 | 2025-03-07 13:30:08 |
| R54.htm | 17628 | 2025-03-07 13:30:08 |
| R55.htm | 57888 | 2025-03-07 13:30:08 |
| R56.htm | 81574 | 2025-03-07 13:30:08 |
| R57.htm | 61228 | 2025-03-07 13:30:08 |
| R58.htm | 30172 | 2025-03-07 13:30:08 |
| R59.htm | 16327 | 2025-03-07 13:30:08 |
| R6.htm | 49164 | 2025-03-07 13:30:08 |
| R60.htm | 12465 | 2025-03-07 13:30:08 |
| R61.htm | 22662 | 2025-03-07 13:30:08 |
| R62.htm | 22448 | 2025-03-07 13:30:08 |
| R63.htm | 12664 | 2025-03-07 13:30:08 |
| R64.htm | 22856 | 2025-03-07 13:30:08 |
| R65.htm | 18541 | 2025-03-07 13:30:08 |
| R66.htm | 11672 | 2025-03-07 13:30:08 |
| R67.htm | 20383 | 2025-03-07 13:30:08 |
| R68.htm | 31702 | 2025-03-07 13:30:08 |
| R69.htm | 34856 | 2025-03-07 13:30:08 |
| R7.htm | 10364 | 2025-03-07 13:30:08 |
| R70.htm | 20614 | 2025-03-07 13:30:08 |
| R71.htm | 9311 | 2025-03-07 13:30:08 |
| R72.htm | 9561 | 2025-03-07 13:30:08 |
| R73.htm | 12188 | 2025-03-07 13:30:08 |
| R74.htm | 11830 | 2025-03-07 13:30:08 |
| R75.htm | 26575 | 2025-03-07 13:30:08 |
| R76.htm | 10868 | 2025-03-07 13:30:08 |
| R77.htm | 30037 | 2025-03-07 13:30:08 |
| R78.htm | 13566 | 2025-03-07 13:30:08 |
| R79.htm | 11119 | 2025-03-07 13:30:08 |
| R8.htm | 95539 | 2025-03-07 13:30:08 |
| R80.htm | 11343 | 2025-03-07 13:30:08 |
| R81.htm | 40405 | 2025-03-07 13:30:08 |
| R82.htm | 18564 | 2025-03-07 13:30:08 |
| R83.htm | 21066 | 2025-03-07 13:30:08 |
| R84.htm | 34675 | 2025-03-07 13:30:08 |
| R85.htm | 35254 | 2025-03-07 13:30:08 |
| R86.htm | 22671 | 2025-03-07 13:30:08 |
| R87.htm | 18980 | 2025-03-07 13:30:08 |
| R88.htm | 9103 | 2025-03-07 13:30:08 |
| R89.htm | 44395 | 2025-03-07 13:30:08 |
| R9.htm | 63182 | 2025-03-07 13:30:08 |
| R90.htm | 12424 | 2025-03-07 13:30:08 |
| R91.htm | 28572 | 2025-03-07 13:30:08 |
| R92.htm | 66403 | 2025-03-07 13:30:08 |
| R93.htm | 49735 | 2025-03-07 13:30:08 |
| R94.htm | 29869 | 2025-03-07 13:30:08 |
| R95.htm | 7896 | 2025-03-07 13:30:08 |
| R96.htm | 83734 | 2025-03-07 13:30:08 |
| R97.htm | 38704 | 2025-03-07 13:30:08 |
| R98.htm | 12033 | 2025-03-07 13:30:08 |
| R99.htm | 16719 | 2025-03-07 13:30:08 |
| report.css | 2768 | 2025-03-07 13:30:08 |
| Show.js | 1086 | 2025-03-07 13:30:08 |