Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.13,16)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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-Subparagraph (SX 210.5-02(22))
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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
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-Paragraph 3
-Subparagraph e
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- Definition

Amount, after accumulated amortization, of debt discount (premium).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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- Definition

Amount of long-term debt and capital lease obligation due after one year or beyond the normal operating cycle, if longer.

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Amount of long-term debt and capital leases due within one year or the normal operating cycle, if longer.

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- Definition

The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a set, unchanging rate.

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Long-Term Debt, Financing and Capital Lease Obligations (Schedule of Long-term Debt Instruments) (Details) - USD ($) $ in Millions	9 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Mar. 31, 2017	Feb. 02, 2017	Oct. 31, 2016
Debt Instrument [Line Items]
Long-term Debt, Gross				$ 6,000
Debt Instrument, Unamortized Premium (Discount), Net	$ (24)		$ 90
Current and Long-term Debt, Financing and Capital Lease Obligations	36,861		40,914
Long Term Debt Financing And Capital Lease Obligations, Current portion	(4,036)		(5,036)
Long-term debt, financing and capital lease obligations	32,825		35,878
Senior Notes [Member] \| Sprint Corporation [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	10,500		10,500
Senior Notes [Member] \| Sprint Nextel Corporation [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	4,780		6,080
Senior Notes [Member] \| Sprint Capital Corporation [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	6,204		6,204
Guaranteed notes [Member] \| Sprint Nextel Corporation [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 2,800		4,000
Secured Debt [Member] \| Sprint Nextel Corporation [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	9.25%
Long-term Debt, Gross	$ 200		200
Secured Debt [Member] \| Sprint Spectrum Co LLC, Sprint Spectrum Co II LLC, Sprint Spectrum Co III LLC [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.36%				3.36%
Long-term Debt, Gross	$ 3,281		3,500
Exchangeable notes [Member] \| Clearwire Communications LLC [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	8.25%
Long-term Debt, Gross	$ 0		629
Redemption price (as a percent)	100.00%
Financing Obligation [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 2,966		1,964
Revolving Credit Facility [Member] \| Secured Revolving Bank Credit Facility expires in Feb 2021[Member] [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate	3.88%
Line of Credit Facility, Amount Outstanding	$ 0		0
Secured term loan [Member] \| Sprint Nextel Corporation [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate	4.13%
Long-term Debt, Gross				$ 4,000
Line of Credit Facility, Amount Outstanding	$ 3,970		4,000
Secured term loan [Member] \| PRWireless HoldCo, LLC Secured Term Loan [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate	6.94%
Line of Credit Facility, Amount Outstanding	$ 183	$ 178	0
Line of Credit [Member] \| Export Development Canada Agreement [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Amount Outstanding			300
Line of Credit [Member] \| Secured Equipment Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Amount Outstanding	555		431
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	334		$ 3,016
Financing Obligations, Capital Lease Obligations and Other [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 1,146
Minimum [Member] \| Senior Notes [Member] \| Sprint Corporation [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.13%
Minimum [Member] \| Senior Notes [Member] \| Sprint Nextel Corporation [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.00%
Minimum [Member] \| Senior Notes [Member] \| Sprint Capital Corporation [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.88%
Minimum [Member] \| Guaranteed notes [Member] \| Sprint Nextel Corporation [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.00%
Minimum [Member] \| Financing Obligation [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	2.44%
Minimum [Member] \| Line of Credit [Member] \| Secured Equipment Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate	3.02%
Minimum [Member] \| Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.35%
Maximum [Member] \| Senior Notes [Member] \| Sprint Corporation [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.88%
Maximum [Member] \| Senior Notes [Member] \| Sprint Nextel Corporation [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	11.50%
Maximum [Member] \| Senior Notes [Member] \| Sprint Capital Corporation [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	8.75%
Maximum [Member] \| Guaranteed notes [Member] \| Sprint Nextel Corporation [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	9.00%
Maximum [Member] \| Financing Obligation [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	2.97%
Maximum [Member] \| Line of Credit [Member] \| Export Development Canada Agreement [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate	4.07%
Maximum [Member] \| Line of Credit [Member] \| Secured Equipment Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate	3.72%
Maximum [Member] \| Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	12.00%