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Intangible Assets - Narrative (Details)		3 Months Ended
Intangible Assets - Narrative (Details)	Apr. 01, 2025 USD ($)	Jun. 30, 2026 USD ($) county	Jun. 30, 2025 USD ($) county	Mar. 31, 2026 USD ($)
Acquired Indefinite-lived Intangible Assets [Line Items]
Impairment charges		$ 0	$ 0
Broadband licenses granted, number of counties \| county		6	62
Exchanges - licenses received		$ 13,522,000	$ 40,618,000
Exchanges - licenses surrendered		(2,869,000)	(6,702,000)
Gain on exchange of intangible assets, net		10,653,000	33,916,000
Payments to acquire intangible assets		6,703,000	3,966,000
Decrease in contingent liability		0	(1,054,000)
Gain on sale of intangible assets		0	961,000
Broadband licenses held for sale		13,000,000	0	$ 0
Disposal Group, Held-for-Sale, Not Discontinued Operations
Acquired Indefinite-lived Intangible Assets [Line Items]
Broadband licenses held for sale		13,000,000.0	0
Licensing Agreements
Acquired Indefinite-lived Intangible Assets [Line Items]
Exchanges - licenses received		13,500,000	40,600,000
Exchanges - licenses surrendered		(2,900,000)	$ (6,700,000)
Broadband licenses transferred, total consideration		0
Reduction in indefinite-lived intangible assets		$ 0
Licensing Agreements \| Lower Colorado River Authority
Acquired Indefinite-lived Intangible Assets [Line Items]
Broadband licenses granted, number of counties \| county			24
Broadband licenses transferred, total consideration			$ 2,200,000
Reduction in indefinite-lived intangible assets			1,200,000
Payments to acquire intangible assets	$ 1,100,000
Decrease in contingent liability			1,100,000
Gain on sale of intangible assets			$ 1,000,000.0
Licensing Agreements \| Oncor Electric Delivery Company LLC
Acquired Indefinite-lived Intangible Assets [Line Items]
Broadband licenses granted, number of counties \| county			3
Reduction in indefinite-lived intangible assets			$ 300,000
Payments to acquire intangible assets			300,000
Gain on sale of intangible assets			$ 8,000