Long-Term Debt, Financing and Capital Lease Obligations (Narrative) (Details)	1 Months Ended			3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 31, 2016 USD ($)	May 31, 2016 USD ($)	Apr. 30, 2016 USD ($)	Dec. 31, 2016 USD ($) site years	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($) site years	Dec. 31, 2015 USD ($)	Dec. 31, 2013 USD ($)	Feb. 02, 2017 USD ($)	Dec. 01, 2016	Dec. 31, 2014 tranche	Jul. 10, 2013 USD ($)
Schedule of Capitalization, Long-term Debt [Line Items]
Sale Leaseback Transaction, Net Book Value				$ 447,000,000	$ 1,200,000,000	$ 447,000,000	$ 1,300,000,000
Sale Leaseback Transaction, Net Proceeds, Financing Activities					600,000,000
Sale Leaseback Transaction, Cumulative Lease Payments						153,000,000
Sale Leaseback Transaction, Net Proceeds, Investing Activities						0	1,136,000,000
Repayments of Accounts Receivable Securitization						502,000,000
Long-term debt issued by 100% owned subsidiary and is fully and unconditionally guaranteed by the parent				22,300,000,000		22,300,000,000
Interest Costs Capitalized						32,000,000	40,000,000
Cash interest payments						1,900,000,000	$ 1,800,000,000
Redeemable notes				31,300,000,000		31,300,000,000
Principal amount of notes with the right to require the Company to repurchase on change of control				$ 25,100,000,000		$ 25,100,000,000
Number of cell sites leased back | site				3,000		3,000
Term in years for cell sites leased back renewal options | years				20		20
Payments for (Proceeds from) Businesses and Interest in Affiliates		$ 181,000,000
Ratio Of Total Indebtedness To Adjusted EBITDA				2.5		2.5
Exchangeable notes [Member] | Clearwire Communications LLC [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Debt Instrument, Interest Rate, Stated Percentage				8.25%		8.25%						8.25%
Fixed amount of cash for a fixed principal amount of notes surrendered that becomes exchangeable at the holder's option												$ 706.21
Fixed principal amount of notes surrendered for a fixed amount of cash that becomes exchangeable at the holder's option												$ 1,000
Long-term Debt, Gross				$ 629,000,000	629,000,000	$ 629,000,000
Unsecured Debt [Member] | Financing Facility [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Debt Issuance Costs, Net				74,000,000		74,000,000
Debt Instrument, Repurchased Face Amount	$ 2,500,000,000
Secured Debt [Member] | Clearwire Communications LLC [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Repayments of Debt				300,000,000
Long-term Debt, Gross				$ 0	300,000,000	$ 0
Secured Debt [Member] | Sprint Spectrum Co LLC, Sprint Spectrum Co II LLC, Sprint Spectrum Co III LLC [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.36%			3.36%		3.36%
Long-term Debt, Gross				$ 3,500,000,000	0	$ 3,500,000,000
Debt instrument face amount	$ 3,500,000,000
Debt Instrument, Term	5 years
Secured Debt, Current				219,000,000		219,000,000
Debt Issuance Costs, Gross	$ 95,000,000
Secured Debt [Member] | Spectrum Financing [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Debt Instrument, Maximum Borrowing Capacity	7,000,000,000
Debt Instrument, Additional Borrowings Available	$ 3,500,000,000
Secured notes [Member] | Clearwire Communications LLC [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Debt Instrument, Interest Rate, Stated Percentage										14.75%
Senior Notes [Member] | Sprint Corporation [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross				10,500,000,000	10,500,000,000	10,500,000,000
Senior Notes [Member] | Sprint Nextel Corporation [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Debt Instrument, Interest Rate, Stated Percentage										6.00%
Repayments of Debt				2,000,000,000
Long-term Debt, Gross				7,280,000,000	9,280,000,000	7,280,000,000
Line of Credit [Member] | Export Development Canada Agreement [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Line of Credit Facility, Amount Outstanding					550,000,000
Line of Credit [Member] | Secured Equipment Credit Facility [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Line of Credit Facility, Amount Outstanding				586,000,000	805,000,000	586,000,000
Line of Credit [Member] | EKN Secured Equipment Credit Facility [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Proceeds from Lines of Credit						127,000,000		$ 1,000,000,000
Line of Credit Facility, Amount Outstanding				127,000,000		127,000,000
Line of Credit [Member] | Finnvera Secured Equipment Credit Facility [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				800,000,000		800,000,000
Number of tranches | tranche											3
Proceeds from Lines of Credit						28,000,000
Line of Credit Facility, Amount Outstanding				168,000,000		168,000,000
Line of Credit [Member] | K-sure Secured Equipment Credit Facility [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				750,000,000		750,000,000
Number of tranches | tranche											3
Proceeds from Lines of Credit						65,000,000
Line of Credit Facility, Amount Outstanding				258,000,000		258,000,000
Line of Credit [Member] | Delcredere / Ducroire (D/D) Secured Equipment Credit Facility [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				250,000,000		250,000,000
Line of Credit Facility, Amount Outstanding				32,000,000		32,000,000
Guaranteed notes [Member] | Sprint Nextel Corporation [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross				4,000,000,000	4,000,000,000	4,000,000,000
Revolving Credit Facility [Member] | Unsecured Revolving Credit Facility expires in 2018 [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				3,300,000,000		3,300,000,000
Line of Credit Facility, Remaining Borrowing Capacity				3,000,000,000		3,000,000,000
Line of Credit Facility, Amount Outstanding				0	$ 0	0
Letter of Credit [Member] | Unsecured Revolving Credit Facility expires in 2018 [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Letters of Credit Outstanding, Amount				$ 274,000,000		$ 274,000,000
Unsecured Revolving Credit Facility expires in 2018 [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Ratio Of Total Indebtedness To Adjusted EBITDA through the quarter ended December 31, 2016				6.25		6.25
Required Ratio Of Total Indebtedness To Adjusted EBITDA for each fiscal quarter ending thereafter through expiration of the revolving credit facility				6.0		6.0
Minimum required cash remaining on hand for operations as part of covenants				$ 2,000,000,000		$ 2,000,000,000
Tranche three and four [Member] | Line of Credit [Member] | Export Development Canada Agreement [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Line of Credit Facility, Amount Outstanding				550,000,000		550,000,000
Network Sale-Leaseback [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Sale Leaseback Transaction, Net Book Value			$ 3,000,000,000	2,500,000,000		2,500,000,000
Sale Leaseback Transaction, Net Proceeds, Financing Activities			2,200,000,000
Long-term Debt and Capital Lease Obligations, Repayments of Principal in Next Twelve Months				300,000,000		300,000,000
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Two				1,900,000,000		1,900,000,000
MLS 2nd Tranche [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Sale Leaseback Transaction, Net Book Value		$ 1,300,000,000		554,000,000		554,000,000
Sale Leaseback Transaction, Net Proceeds, Investing Activities			$ 1,100,000,000
Tower financing [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Sale Leaseback Transaction, Net Book Value				$ 0		0
FCC Licenses [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Indefinite-lived Intangible Assets Acquired						85,000,000
Other, Net [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Payments for (Proceeds from) Businesses and Interest in Affiliates						$ 96,000,000
Subsequent Event [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross									$ 6,000,000,000
Minimum [Member] | Successor [Member] | Senior Notes [Member] | Sprint Corporation [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Debt Instrument, Interest Rate, Stated Percentage				7.13%		7.13%
Minimum [Member] | Successor [Member] | Guaranteed notes [Member] | Sprint Nextel Corporation [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Debt Instrument, Interest Rate, Stated Percentage				7.00%		7.00%
Spectrum Assets [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Concentration Risk, Percentage	14.00%