Organization and Business Activities - Asset Purchase Agreement (Details) $ in Millions	Apr. 01, 2020	Jul. 26, 2019 USD ($) item
Asset Purchase Agreement
Period in which at least 20% of population served to avoid payment of damages		3 years
Number of spectrum bands | item		4
600 MHz Licenses | Not later than June 14, 2022 | Minimum
Asset Purchase Agreement
Percent Of Coverage On Available Licensed Geographic Areas		70.00%
600 MHz Licenses | Not later than June 14, 2025 | Maximum
Asset Purchase Agreement
Percent Of Coverage On Available Licensed Geographic Areas		75.00%
AWS-4 Licenses | Not later than June 14, 2022 | Minimum
Asset Purchase Agreement
Percent Of Coverage On Available Licensed Geographic Areas		20.00%
AWS-4 Licenses | Not later than June 14, 2023 | Maximum
Asset Purchase Agreement
Percent Of Coverage On Available Licensed Geographic Areas		70.00%
Lower 700 MHz E Block licenses | Not later than June 14, 2022 | Minimum
Asset Purchase Agreement
Percent Of Coverage On Available Licensed Geographic Areas		20.00%
Lower 700 MHz E Block licenses | Not later than June 14, 2023 | Maximum
Asset Purchase Agreement
Percent Of Coverage On Available Licensed Geographic Areas		70.00%
AWS H Block licenses | Not later than June 14, 2022 | Minimum
Asset Purchase Agreement
Percent Of Coverage On Available Licensed Geographic Areas		20.00%
AWS H Block licenses | Not later than June 14, 2023 | Maximum
Asset Purchase Agreement
Percent Of Coverage On Available Licensed Geographic Areas		70.00%
Asset Purchase Agreement
Asset Purchase Agreement
Purchase price		$ 1,400
Spectrum Purchase Agreement
Asset Purchase Agreement
Purchase price		$ 3,590
Option Agreement
Asset Purchase Agreement
Period after closing of prepaid business sale, transfer asset request is admissible		1 year
Period within closing of prepaid business sale, required to offer nationwide postpaid retail mobile wireless service		1 year
Period within entry of final judgment	5 years
Percentage of purchase price		10.00%
Percentage of population served		20.00%
Period in which at least 20% of population served to avoid payment of damages		3 years
Status of negotiation period		90 days
Threshold period for involvement of DOJ		180 days
Period obliged to provide DOJ with description of deployment efforts		180 days
Term of final judgement from the date of its entry with the District Court.	7 years	7 years
Term of final judgement if DOJ gives notice	5 years
Damages To Be Paid In Case Of Breach Of Agreement		$ 360
Spectrum Lease Period		6 years
Option Agreement | AWS-4 Licenses
Asset Purchase Agreement
Damages To Be Paid In Case Of Breach Of Agreement		$ 2,200