Acquisitions and Divestitures (Details) - USD ($) $ / shares in Units, $ in Millions			1 Months Ended	6 Months Ended
	Oct. 17, 2024	Sep. 04, 2024	Feb. 28, 2021	Jun. 30, 2025	Jun. 30, 2024
Business Combination [Line Items]
Payments for deposits				$ 234	$ 613
Spectrum Licenses, United States Cellular Corporation (UScellular)
Business Combination [Line Items]
Asset acquisition, consideration transferred	$ 1,000
Spectrum licenses | Spectrum Licenses, C-Band
Business Combination [Line Items]
Estimated clearing and incentive costs			$ 7,500
Spectrum licenses | Spectrum Licenses, C-Band | Projected Clearing Costs
Business Combination [Line Items]
Payments for deposits					$ 269
Frontier
Business Combination [Line Items]
Business acquisition, share price (in dollars per share)		$ 38.50
Business combination, termination fee		$ 590
Frontier | Frontier
Business Combination [Line Items]
Business combination, termination fee		$ 320