Goodwill, Spectrum License Transactions and Other Intangible Assets - Schedule of Fair Value of Intangible Assets Acquired in Merger (Details) - Sprint $ in Millions	Apr. 01, 2020 USD ($)
Finite-Lived Intangible Assets [Line Items]
Total intangible assets acquired	$ 51,680
Tradenames
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	2 years
Finite-lived, fair value	$ 207
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	8 years
Finite-lived, fair value	$ 4,900
Favorable spectrum leases
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	18 years
Finite-lived, fair value	$ 745
Other intangible assets
Finite-Lived Intangible Assets [Line Items]
Weighted Average Useful Life (in years)	7 years
Finite-lived, fair value	$ 428
Spectrum Licenses
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived, Fair Value (in millions)	$ 45,400

Indefinite-lived and Finite-lived Intangible Assets Acquired

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+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
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Amount of increase in assets, excluding financial assets and goodwill, lacking physical substance with an indefinite life, from an acquisition.

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