Investments (Narrative) (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	35 Months Ended				3 Months Ended		9 Months Ended
	Sep. 30, 2011	Nov. 02, 2011	Dec. 31, 2010	Dec. 31, 2008	Sep. 30, 2011 Clearwire [Member]	Sep. 30, 2010 Clearwire [Member]	Sep. 30, 2011 Clearwire [Member]	Sep. 30, 2010 Clearwire [Member]	Sep. 30, 2011 Clearwire Class B Voting [Member]	Jun. 01, 2011 Clearwire Class B Voting [Member]	May 31, 2011 Clearwire Class B Voting [Member]	Sep. 30, 2011 Clearwire Class B Non-voting [Member]
Sprint share in percentage of non-controlling interest in Clearwire									49.70%		53.70%	54.00%
Clearwire shares owned									454			532
Carrying value of non-controlling interest					$ 1,800,000,000		$ 1,800,000,000
Equity Method Investment, Shares Surrendered										78
Interest Rate of Clearwire Note Receivable	12.00%
Notes Receivable, Related Parties			177,000,000		178,000,000		178,000,000
Equity in losses from Clearwire					271,000,000	298,000,000	1,283,000,000	848,000,000
Equity Method Investment, decline in value	2,100,000,000
Equity method investment book value per share	$ 3.41			$ 10.65
Price per share of Clearwire's stock	$ 2.33	$ 2.04
Excess of carrying value per share compared to closing per share stock price of equity method investment	$ 575,000,000	$ 729,000,000