Intangible Assets - Narrative (Details) $ in Millions	3 Months Ended		12 Months Ended		39 Months Ended
	Mar. 31, 2022 USD ($) license	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($) license	Dec. 31, 2020 USD ($)	Dec. 31, 2024 USD ($)
Licenses
Cash paid for intangible assets	$ 568	$ 1,261
Auction 107
Licenses
Licenses won | license			254
Total winning bid			$ 1,283
FCC upfront payment				$ 30
Cash paid for intangible assets			36
Auction 107 | Subsequent event
Licenses
Cash paid for intangible assets					$ 187
Auction 110
Licenses
Licenses won | license	380
Total winning bid	$ 580
FCC upfront payment			$ 20