Investments (Narrative) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended				12 Months Ended							3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Dec. 17, 2012	Jan. 02, 2014 Additional Notes Receivable [Member]	Jan. 02, 2012 Additional Notes Receivable [Member] terms	Nov. 28, 2008 Notes Receivable [Member]	May 01, 2013 Financing Agreement entered into in December 2012 [Member]	Mar. 31, 2013 Financing Agreement entered into in December 2012 [Member] draws	Dec. 17, 2012 Financing Agreement entered into in December 2012 [Member]	Mar. 31, 2013 Clearwire Class B Non Voting [Member]	Mar. 31, 2013 Clearwire [Member]	Mar. 31, 2012 Clearwire [Member]	May 01, 2013 Clearwire [Member] Financing Agreement entered into in December 2012 [Member]	Mar. 31, 2013 Non-controlling economic interest [Member] Clearwire Class B Non Voting [Member]	Mar. 31, 2013 Non-controlling economic interest [Member] Clearwire Communications LLC [Member]
Schedule of Equity Method Investments [Line Items]
Debt Instrument, Unused Borrowing Capacity, Amount														$ 400
Sprint share in percentage of non-controlling interest in Clearwire											50.20%				2.10%	48.10%
Carrying value of non-controlling interest											472
Notes Receivable, Related Parties	248		320			150
Interest Rate of Note Receivable, Related Parties						11.50%	12.00%
Number of installments						2
Future payment on notes receivable, related party					75
Draws Not Taken by Investee									2
Amount elected to forego									160
Exchangeable notes, related party	80		0	800
Amount of individual draw of exchangeable note				80						80
Amount funded by the Company								240	80
Common Stock, Par or Stated Value Per Share	$ 2		$ 2
Equity in losses from Clearwire												202	290
Asset Impairment Charges	0	84											40
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity	271
Prepaid Expenses and Other Current Assets, Related Parties	127		78
Accounts Payable, Related Parties, Current	80		79
Related Party Transaction, Amounts of Transaction	$ 101	$ 105