Intangible Assets (Intangible Assets Subject to Amortization) (Details) (USD $) In Millions, unless otherwise specified															3 Months Ended
Jun. 30, 2014 Successor [Member]	Mar. 31, 2014 Successor [Member]	Jun. 30, 2014 Successor [Member] Customer Relationships [Member]	Mar. 31, 2014 Successor [Member] Customer Relationships [Member]	Jun. 30, 2014 Successor [Member] Favorable spectrum leases [Member]	Mar. 31, 2014 Successor [Member] Favorable spectrum leases [Member]	Jun. 30, 2014 Successor [Member] Favorable tower leases [Member]	Mar. 31, 2014 Successor [Member] Favorable tower leases [Member]	Jun. 30, 2014 Successor [Member] Trademarks [Member]	Mar. 31, 2014 Successor [Member] Trademarks [Member]	Jun. 30, 2014 Successor [Member] Other Finite Lived Intangible Assets [Member]	Mar. 31, 2014 Successor [Member] Other Finite Lived Intangible Assets [Member]	Jun. 30, 2014 Successor [Member] Finite Lived Intangible Assets Excluding Customer Relationships [Member]	Mar. 31, 2014 Successor [Member] Finite Lived Intangible Assets Excluding Customer Relationships [Member]	Jun. 30, 2014 Minimum [Member] Customer Relationships [Member]	Jun. 30, 2014 Minimum [Member] Favorable tower leases [Member]	Jun. 30, 2014 Minimum [Member] Other Finite Lived Intangible Assets [Member]	Jun. 30, 2014 Maximum [Member] Customer Relationships [Member]	Jun. 30, 2014 Maximum [Member] Favorable spectrum leases [Member]	Jun. 30, 2014 Maximum [Member] Favorable tower leases [Member]	Jun. 30, 2014 Maximum [Member] Trademarks [Member]	Jun. 30, 2014 Maximum [Member] Other Finite Lived Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life															4 years	3 years	4 years	8 years	23 years	7 years	34 years	10 years
Gross Carrying Value	$ 8,979	$ 8,976	$ 6,923	$ 6,923	$ 884	$ 884	$ 589	$ 589	$ 520	$ 520	$ 63	$ 60	$ 2,056	$ 2,053
Accumulated Amortization	(1,860)	(1,418)	(1,687)	(1,289)	(40)	(30)	(107)	(80)	(16)	(12)	(10)	(7)	(173)	(129)
Net Carrying Value	$ 7,119	$ 7,558	$ 5,236	$ 5,634	$ 844	$ 854	$ 482	$ 509	$ 504	$ 508	$ 53	$ 53	$ 1,883	$ 1,924

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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- Definition

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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- Definition

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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