Organization and Business Activities - Asset Purchase Agreement (Details) $ in Millions	Jul. 26, 2019 USD ($) item employee
Asset Purchase Agreement
Number of spectrum bands | item	4
600 MHz Licenses | Not later than June 14, 2023 | 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
Period after provisioning new or existing customers of prepaid business	15 days
Period after final judgment	5 days
Number of employees expected to transfer | employee	480
Right to terminate agreement, period	12 months
Right to terminate agreement after closing of merger period	90 days
Sellers right to terminate agreement, period	90 days
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	90 days
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
Term of final judgement if DOJ gives notice	5 years
Damages To Be Paid In Case Of Breach Of Agreement	$ 360
Public Commitment Period	60 days
Spectrum Lease Period	6 years
Number of spectrum bands | item	4
Option Agreement | AWS-4 Licenses
Asset Purchase Agreement
Damages To Be Paid In Case Of Breach Of Agreement	$ 2,200