| Disaggregation of Revenue [Table Text Block] |
| | | | Three Months Ended | |
| | Reportable | | June 30, | |
| | Segment | | 2026 | | | 2025 | |
| Region: | | | | | | | | | |
| North America | Grid | | | 43,162 | | | | 37,772 | |
| South America | Grid | | | 21,980 | | | | 248 | |
| Asia Pacific | Grid | | | 4,197 | | | | 18,304 | |
| EMEA | Grid | | | 6,984 | | | | 3,763 | |
| Total | Grid | | $ | 76,323 | | | $ | 60,087 | |
| | | | | | | | | | |
| Region: | | | | | | | | | |
| Asia Pacific | Wind | | | 17,740 | | | | 12,271 | |
| EMEA | Wind | | | 10 | | | | — | |
| Total | | $ | 17,750 | | | $ | 12,271 | |
|
| Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] |
| | | Unbilled Accounts Receivable | | | Deferred Program Costs | | | Contract Liabilities | |
| Beginning balance as of March 31, 2026 | | $ | 14,875 | | | $ | 7,579 | | | $ | 93,331 | |
| Increases for costs incurred to fulfill performance obligations | | | — | | | | 4,731 | | | | — | |
| Increase (decrease) due to customer billings | | | (15,027 | ) | | | — | | | | 59,566 | |
| Decrease due to cost recognition on completed performance obligations | | | — | | | | (6,290 | ) | | | — | |
| Increase (decrease) due to recognition of revenue based on transfer of control of performance obligations | | | 9,742 | | | | — | | | | (50,423 | ) |
| Other changes and FX impact | | | (30 | ) | | | 5 | | | | 144 | |
| Ending balance as of June 30, 2026 | | $ | 9,560 | | | $ | 6,025 | | | $ | 102,618 | |
| | | Unbilled Accounts Receivable | | | Deferred Program Costs | | | Contract Liabilities | |
| Beginning balance as of March 31, 2025 | | $ | 6,376 | | | $ | 5,756 | | | $ | 76,133 | |
| Increases for costs incurred to fulfill performance obligations | | | — | | | | 3,907 | | | | — | |
| Increase (decrease) due to customer billings | | | (3,189 | ) | | | — | | | | 30,863 | |
| Decrease due to cost recognition on completed performance obligations | | | — | | | | (4,093 | ) | | | — | |
| Increase (decrease) due to recognition of revenue based on transfer of control of performance obligations | | | 6,876 | | | | — | | | | (32,108 | ) |
| Other changes and FX impact | | | 20 | | | | 46 | | | | 1,003 | |
| Ending balance as of June 30, 2025 | | $ | 10,083 | | | $ | 5,616 | | | $ | 75,891 | |
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