Investments (Narrative) (Details) (USD $)	3 Months Ended			3 Months Ended					12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011	Mar. 31, 2012 Clearwire [Member]	Mar. 31, 2011 Clearwire [Member]	Dec. 31, 2011 Clearwire [Member]	Mar. 31, 2012 Clearwire Class B Voting [Member]	Mar. 31, 2012 Clearwire Class B Non-voting [Member]	Jan. 02, 2014 Additional Notes Receivable [Member] Clearwire [Member]	Jan. 02, 2012 Additional Notes Receivable [Member] Clearwire [Member] terms	Nov. 28, 2008 Notes Receivable [Member] Clearwire [Member]
Schedule of Equity Method Investments [Line Items]
Sprint share in percentage of non-controlling interest in Clearwire							47.10%	50.00%
Carrying value of non-controlling interest				$ 1,400,000,000
Notes Receivable, Related Parties				309,000,000		178,000,000				150,000,000
Interest Rate of Note Receivable, Related Parties										11.50%	12.00%
Number of installments										2
Future payment on notes receivable, related party									75,000,000
Equity in losses from Clearwire				290,000,000	418,000,000
Asset impairments	84,000,000	0		40,000,000	92,000,000
Price per share of Clearwire's stock				$ 2.28
Equity method investment book value per share				$ 1.99
Excess of Clearwire's closing stock price over the carrying value per share of Sprint's investment in Clearwire				204,000,000
Prepaid Expenses and Other Current Assets, Related Parties	51,000,000		5,000,000
Accounts Payable, Related Parties, Current	155,000,000		77,000,000
Related Party Transaction, Amounts of Transaction	$ 105,000,000	$ 46,000,000