Other Financial Information - Schedule of Other Current Assets, Net (Details) - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025
Prepaid Expenses and Other Current Assets [Abstract]
Prepaid expenses	$ 371	$ 404
Income tax receivable	12	468
Materials, supplies and inventory	121	165
Contract assets	14	18
Other	64	18
Total other current assets, net	817	1,307
Held for sale \| Mass Markets Fiber-to-the Home Business
Other Current Assets [Line Items]
Other current assets, net		30
Acquisition Costs
Prepaid Expenses and Other Current Assets [Abstract]
Contract costs	84	98
Fulfillment Costs
Prepaid Expenses and Other Current Assets [Abstract]
Contract costs	$ 151	$ 136

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