Acquisitions and Divestitures - Spectrum License Transactions (Details) - USD ($) $ in Millions		1 Months Ended	12 Months Ended
	Oct. 17, 2024	Feb. 28, 2021	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Business Acquisition [Line Items]
Payments for intangible assets			$ 900	$ 5,796	$ 3,653
Spectrum Licenses, United States Cellular Corporation (UScellular)
Business Acquisition [Line Items]
Asset acquisition, consideration transferred	$ 1,000
Spectrum Licenses, C-Band | Spectrum Licenses
Business Acquisition [Line Items]
Estimated clearing and incentive costs		$ 7,500
Spectrum Licenses, C-Band | Spectrum Licenses | Satellite Agreements
Business Acquisition [Line Items]
Payments for intangible assets					310
Costs incurred for license agreements acquired					340
Spectrum Licenses, C-Band | Spectrum Licenses | Projected Clearing Costs
Business Acquisition [Line Items]
Payments for intangible assets			$ 269	$ 4,300	$ 1,600