Long-Term Debt, Financing and Capital Lease Obligations (Narrative) (Details) (USD $)						6 Months Ended									6 Months Ended																3 Months Ended	6 Months Ended						0 Months Ended	3 Months Ended
	Sep. 30, 2014 site years	Jul. 10, 2013	Sep. 30, 2014 Exchangeable notes [Member] Clearwire Communications LLC [Member]	Jul. 10, 2013 Exchangeable notes [Member] Clearwire Communications LLC [Member]	Sep. 30, 2014 Secured Debt [Member] Clearwire Communications LLC [Member]	Sep. 30, 2014 Secured Debt [Member] iPCS Inc Secured Notes [Member]	Sep. 11, 2013 Senior Notes [Member] Sprint Communications Inc. Guaranteed Notes due 2021 [Member]	Sep. 11, 2013 Senior Notes [Member] Sprint Corporation 7.875% [Member]	Dec. 12, 2013 Senior Notes [Member] Sprint Corporation 7.125% [Member] [Member]	Sep. 30, 2014 Line of Credit [Member] Secured Equipment Credit Facility [Member]	Sep. 30, 2014 Revolving Credit Facility [Member] Unsecured Revolving Credit Facility expires in 2018 [Member]	Feb. 10, 2014 Revolving Credit Facility [Member] Unsecured Revolving Credit Facility expires in 2018 [Member]	Apr. 02, 2013 Revolving Credit Facility [Member] Unsecured Revolving Credit Facility expires in 2018 [Member]	Sep. 30, 2014 Letter of Credit [Member] Unsecured Revolving Credit Facility expires in 2018 [Member]	Sep. 30, 2014 Successor [Member]	Sep. 30, 2013 Successor [Member]	Sep. 30, 2014 Successor [Member] Exchangeable notes [Member] Clearwire Communications LLC [Member]		Mar. 31, 2014 Successor [Member] Exchangeable notes [Member] Clearwire Communications LLC [Member]		Sep. 30, 2014 Successor [Member] Secured Debt [Member] Clearwire Communications LLC [Member]		Mar. 31, 2014 Successor [Member] Secured Debt [Member] Clearwire Communications LLC [Member]		Sep. 30, 2014 Successor [Member] Secured Debt [Member] iPCS Inc Secured Notes [Member]	Mar. 31, 2014 Successor [Member] Secured Debt [Member] iPCS Inc Secured Notes [Member]	Sep. 30, 2014 Successor [Member] Senior Notes [Member] Sprint Corporation [Member]	Mar. 31, 2014 Successor [Member] Senior Notes [Member] Sprint Corporation [Member]	Sep. 30, 2014 Successor [Member] Senior Notes [Member] Sprint Nextel Corporation Guaranteed Notes [Member]	Mar. 31, 2014 Successor [Member] Senior Notes [Member] Sprint Nextel Corporation Guaranteed Notes [Member]	Sep. 30, 2014 Successor [Member] Line of Credit [Member] Secured Equipment Credit Facility [Member]	Sep. 30, 2014 Successor [Member] Line of Credit [Member] Secured Equipment Credit Facility [Member]	Mar. 31, 2014 Successor [Member] Line of Credit [Member] Secured Equipment Credit Facility [Member]	Sep. 30, 2014 Successor [Member] Guaranteed notes [Member] Sprint Nextel Corporation Guaranteed Notes [Member]	Mar. 31, 2014 Successor [Member] Guaranteed notes [Member] Sprint Nextel Corporation Guaranteed Notes [Member]	Sep. 30, 2014 Successor [Member] Revolving Credit Facility [Member] Unsecured Revolving Credit Facility expires in 2018 [Member]	Mar. 31, 2014 Successor [Member] Revolving Credit Facility [Member] Unsecured Revolving Credit Facility expires in 2018 [Member]	Jul. 10, 2013 Predecessor [Member]	Jul. 10, 2013 Predecessor [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Principal of debt outstanding	$ 9,000,000,000
Long-term debt issued by 100% owned subsidiary and is fully and unconditionally guaranteed by the parent	20,100,000,000
Interest Costs Capitalized															25,000,000	14,000,000																						1,000,000	14,000,000
Cash interest payments															1,200,000,000	309,000,000																						6,000,000	509,000,000
Redeemable notes	28,600,000,000
Principal amount of notes with the right to require the Company to repurchase on change of control	20,100,000,000
Principal amount of notes with the right to require the Company to repurchase on change of control					300,000,000
Percentage of principal amount required to repurchase notes on change of control	101.00%
Debt Instrument, Interest Rate, Stated Percentage				8.25%			7.25%	7.875%	7.125%								8.25%				14.75%
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
Total cash consideration payable upon an exchange of all principal amount of notes outstanding			444,000,000
Long-term Debt, Gross				629,000,000													629,000,000	[1]	629,000,000	[1]	300,000,000	[1]	300,000,000	[1]	0	181,000,000	9,000,000,000	9,000,000,000	9,280,000,000	9,280,000,000				4,000,000,000	4,000,000,000
Debt Instrument, Face Amount							2,250,000,000	4,250,000,000	2,500,000,000
Repayments of Long-term Debt						181,000,000
Line of Credit Facility, Maximum Borrowing Capacity												3,300,000,000	3,000,000,000
Letters of Credit Outstanding, Amount														918,000,000
Line of Credit Facility, Remaining Borrowing Capacity											2,400,000,000
Line of Credit Facility, Amount Outstanding										1,000,000,000																					635,000,000	635,000,000	762,000,000			0	0
Debt Instrument, Annual Principal Payment																															$ 127,000,000	$ 127,000,000
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate																															2.03%	2.03%
Debt Instrument, Interest Rate, Effective Percentage										6.00%
Number of cell sites leased back	3,000
Term in years for cell sites leased back renewal options	20
Ratio Of Total Indebtedness To Adjusted EBITDA	2.5

[1] Notes of Clearwire Communications LLC are also direct obligations of Clearwire Finance, Inc. and are guaranteed by certain Clearwire subsidiaries.