| Disaggregation of Revenue [Table Text Block] |
| | | Three Months Ended | |
| (In thousands) | | March 31, 2026 | | | March 31, 2025 | |
| | | | | | | Display | | | | | | | Display | |
| | | Lighting | | | Solutions | | | Lighting | | | Solutions | |
| | | Segment | | | Segment | | | Segment | | | Segment | |
| Timing of revenue recognition | | | | | | | | | | | | | | | | |
| Products and services transferred at a point in time | | $ | 48,843 | | | $ | 79,350 | | | $ | 49,258 | | | $ | 60,215 | |
| Products and services transferred over time | | | 11,195 | | | | 11,137 | | | | 9,709 | | | | 13,299 | |
| | | $ | 60,038 | | | $ | 90,487 | | | $ | 58,967 | | | $ | 73,514 | |
| | | | | | | | | | | | | | | | | |
| Type of Product and Services | | | | | | | | | | | | | | | | |
| Lighting, poles, electronic components | | $ | 59,450 | | | $ | - | | | $ | 58,363 | | | $ | - | |
| Signage and display Products | | | - | | | | 76,134 | | | | - | | | | 58,459 | |
| Project management, installation services, shipping and handling | | | 588 | | | | 14,353 | | | | 604 | | | | 15,055 | |
| | | $ | 60,038 | | | $ | 90,487 | | | $ | 58,967 | | | $ | 73,514 | |
| | | Nine Months Ended | |
| (In thousands) | | March 31, 2026 | | | March 31, 2025 | |
| | | | | | | Display | | | | | | | Display | |
| | | Lighting | | | Solutions | | | Lighting | | | Solutions | |
| | | Segment | | | Segment | | | Segment | | | Segment | |
| Timing of revenue recognition | | | | | | | | | | | | | | | | |
| Products and services transferred at a point in time | | $ | 161,877 | | | $ | 224,557 | | | $ | 145,835 | | | $ | 190,355 | |
| Products and services transferred over time | | | 33,887 | | | | 34,455 | | | | 29,779 | | | | 52,341 | |
| | | $ | 195,764 | | | $ | 259,012 | | | $ | 175,614 | | | $ | 242,696 | |
| | | | | | | | | | | | | | | | | |
| Type of Product and Services | | | | | | | | | | | | | | | | |
| Lighting, poles, electronic components | | $ | 193,995 | | | $ | - | | | $ | 173,710 | | | $ | - | |
| Signage and display Products | | | - | | | | 216,302 | | | | - | | | | 192,634 | |
| Project management, installation services, shipping and handling | | | 1,769 | | | | 42,710 | | | | 1,904 | | | | 50,062 | |
| | | $ | 195,764 | | | $ | 259,012 | | | $ | 175,614 | | | $ | 242,696 | |
|