Spectrum Hosting (Narrative) (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	3 Months Ended		6 Months Ended
	Apr. 30, 2012	Mar. 31, 2012 years mHZ gHZ	Mar. 31, 2011	Dec. 31, 2011
Spectrum hosting [Line Items]
MHz licenses utilized in iDEN network		800
Gigahertz (GHz) licenses utilized in the code division multiple access network		1.9
Term of Arrangement		15
Gigahertz expected to be utilized to deploy 4G LTE		1.6
Cash received for Spectrum Hosting Agreement				$ 310
Payment received for incremental costs or obligations incurred by the Company for Spectrum Hosting		236	0
Amount of advanced payment refunded by the Company	2	65
Amount of payment potentially refunded, subject to unwind and termination provisions		9
Asset impairments		84	0
Net gain (loss) related to non-cancellable executory		170
Capitalized assets specific to the spectrum hosting [Member]
Spectrum hosting [Line Items]
Asset impairments		$ 66