Intangible Assets (Narrative) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended		3 Months Ended	9 Months Ended	3 Months Ended		6 Months Ended
	Sep. 30, 2013 mHZ gHZ	Sep. 30, 2012 mHZ	Jun. 30, 2013 Customer Relationships [Member]	Sep. 30, 2013 Customer Relationships [Member]	Sep. 30, 2013 Successor [Member]	May 17, 2013 FCC Licenses [Member]	Jul. 10, 2013 FCC Licenses [Member] Predecessor [Member]	Jul. 09, 2013 Clearwire Acquisition [Member] FCC Licenses [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gigahertz (GHz) licenses utilized in the code division multiple access network	1.9
MHz licenses utilized in iDEN network	800
MHz licenses utilized in the integrated digital enhanced network		900
Fair value of indefinite lived intangible assets acquired in asset acquisition transaction						$ 605
Indefinite-lived Intangible Assets Acquired								11,900
Payments directly attributable to performance under report and order, net change related to FCC licenses							91
Goodwill, Acquired During Period					6,800
Finite-lived Intangible Assets Acquired			32
Reduction In Carrying Value And Accumulated Amortization Of Fully Amortized Intangible Assets				$ 234