Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Disaggregation of Revenue [Line Items]
Total spectrum revenue	$ 6,501	$ 6,031
Total spectrum revenue
Disaggregation of Revenue [Line Items]
Total spectrum revenue	6,501	6,031
Total spectrum revenue \| Ameren Corporation
Disaggregation of Revenue [Line Items]
Total spectrum revenue	824	737
Total spectrum revenue \| Evergy
Disaggregation of Revenue [Line Items]
Total spectrum revenue	1,541	1,542
Total spectrum revenue \| Xcel Energy
Disaggregation of Revenue [Line Items]
Total spectrum revenue	3,524	3,205
Total spectrum revenue \| TECO
Disaggregation of Revenue [Line Items]
Total spectrum revenue	612	0
Total spectrum revenue \| Motorola
Disaggregation of Revenue [Line Items]
Total spectrum revenue	$ 0	$ 547

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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+ Details