Other Financial Information - Other Current Assets (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Other Current Assets [Line Items]
Prepaid expenses	$ 30	$ 98
Other	0	2
Total other current assets, net	77	152
Held-for-sale | Mass Markets Fiber-To-The Home Business
Other Current Assets [Line Items]
Other current assets, net reclassified to held for sale	8
Acquisition Costs
Other Current Assets [Line Items]
Contract costs	21	26
Fulfillment Costs
Other Current Assets [Line Items]
Contract costs	$ 26	$ 26