v3.26.1
BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Basis of Presentation (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended 12 Months Ended
Aug. 11, 2026
Jun. 30, 2026
Mar. 31, 2026
Jun. 30, 2025
Mar. 31, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Product and Service, Revenue [Line Items]                
Net loss   $ (877) $ (140) $ (231) $ (268) $ (1,017) $ (499) $ (1,000)
Net cash used in operating activities   (819)   $ (215)   (750) $ (487) (1,400)
Advance for investment in joint venture   $ 522       $ 522   $ 156
Asakura Energy Storage Power Plant                
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Product and Service, Revenue [Line Items]                
Ownership interest, percentage   35.00%       35.00%    
Total expected investment commitment   $ 1,100       $ 1,100    
Asakura Energy Storage Power Plant | Subsequent Event                
Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Product and Service, Revenue [Line Items]                
Remaining balance, expected to be funded $ 565