Business Combination, Required Financing Fees by Acquirer to Affiliate Upon Consummation

No definition available.

Name:	tmus_BusinessCombinationRequiredFinancingFeesByAcquirerToAffiliateUponConsummation
Namespace Prefix:	tmus_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Business Combination, Required Financing Fees by Acquirer to Third Party Note Holders Upon Consummation

+ References

No definition available.

+ Details

Name:	tmus_BusinessCombinationRequiredFinancingFeesByAcquirerToThirdPartyNoteHoldersUponConsummation
Namespace Prefix:	tmus_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Debt Instrument, Number of Instruments

+ References

No definition available.

+ Details

Name:	tmus_DebtInstrumentNumberOfInstruments
Namespace Prefix:	tmus_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Principal Amount Outstanding

+ References

No definition available.

+ Details

Name:	tmus_DebtInstrumentPrincipalAmountOutstanding
Namespace Prefix:	tmus_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Debt Instrument, Redemption Premium

+ References

No definition available.

+ Details

Name:	tmus_DebtInstrumentRedemptionPremium
Namespace Prefix:	tmus_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line of Credit Facility, Secured Indebtedness, Limit, Percentage

+ References

No definition available.

+ Details

Name:	tmus_LineofCreditFacilitySecuredIndebtednessLimitPercentage
Namespace Prefix:	tmus_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Notes Issued and Outstanding, Principal Amount

+ References

No definition available.

+ Details

Name:	tmus_NotesIssuedandOutstandingPrincipalAmount
Namespace Prefix:	tmus_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Reimbursement of Commitment Letter Fees

+ References

No definition available.

+ Details

Name:	tmus_ReimbursementOfCommitmentLetterFees
Namespace Prefix:	tmus_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Secured Debt to Cash Flow, Ratio

+ References

No definition available.

+ Details

Name:	tmus_SecuredDebttoCashFlowRatio
Namespace Prefix:	tmus_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Special Purpose Entity, Securitization Program, Amount

+ References

No definition available.

+ Details

Name:	tmus_SpecialPurposeEntitySecuritizationProgramAmount
Namespace Prefix:	tmus_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- 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.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of the required periodic payments applied to principal.

+ References

+ Details

Name:	us-gaap_DebtInstrumentPeriodicPaymentPrincipal
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph e
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

Name:	us-gaap_DebtInstrumentRedemptionPricePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of the original debt instrument that was repurchased.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentRepurchasedFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of operating lease income from lease payments paid and payable to lessor. Excludes variable lease payments not included in measurement of lease receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 270
-SubTopic 10
-Section 50
-Paragraph 6A
-URI http://asc.fasb.org/extlink&oid=121640914&loc=SL77927221-108306

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121576215&loc=SL77919372-209981

+ Details

Name:	us-gaap_OperatingLeaseLeaseIncomeLeasePayments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow for loan and debt issuance costs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585

+ Details

Name:	us-gaap_PaymentsOfFinancingCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3255-108585

+ Details

Name:	us-gaap_ProceedsFromIssuanceOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585

+ Details

Name:	us-gaap_RepaymentsOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.4)
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227

+ Details

Name:	us-gaap_SellingGeneralAndAdministrativeExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.16(a))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.16)
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

+ Details

Name:	us-gaap_SeniorNotes
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19)(a))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16)(a)(1))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(13))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

+ Details

Name:	us-gaap_ShortTermBorrowings
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227

+ Details

Name:	us-gaap_WriteOffOfDeferredDebtIssuanceCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_DebtInstrumentAxis=tmus_SecuredBridgeLoanFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=tmus_A6.500SeniorNotesdue2024Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=tmus_SeniorNotesDue20255.125Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=srt_AffiliatedEntityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=tmus_A6.375SeniorNotesdue2025Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=tmus_IncrementalTermLoanFacilityDue2022Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=tmus_IncrementalTermLoanFacilityDue2024Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=tmus_A5.300SeniorNotesdue2021Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=tmus_SeniorNotesDue20275.375Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=tmus_SpectrumFinancingSpecialPurposeEntityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=tmus_SeniorNotesDue20215125Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=tmus_SeniorNotesDue20207000Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=tmus_SeniorSecuredSeries20161A1NotesDue20213360Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=tmus_SprintCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=tmus_CreditFacilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=tmus_SecuredTermLoanFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=tmus_SeniorSecuredSeries20181A1NotesDue20254738Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=tmus_SeniorSecuredSeries20181A2NotesDue20285152Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=tmus_DeutscheTelekomAGMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_LongTermDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=tmus_ExistingSprintSpectrumNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=tmus_SeniorNotesDue20246000Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=tmus_SprintCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt - Financing Matters Agreement, Senior Notes to Affiliates, Spectrum Financing and Consents on Debt to Third-Parties (Details)						3 Months Ended		12 Months Ended
	Sep. 01, 2020 USD ($)	Jul. 04, 2020 USD ($)	Apr. 09, 2020 USD ($)	Apr. 01, 2020 USD ($)	May 18, 2018 USD ($)	Dec. 31, 2020 USD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Oct. 28, 2020 USD ($)	Oct. 06, 2020 USD ($)	Aug. 15, 2020 USD ($)	Jun. 24, 2020 USD ($)	Mar. 31, 2018 USD ($) note
Debt Instrument [Line Items]
Other								$ (47,000,000)
Principal Amount						$ 30,447,000,000		30,447,000,000
Payments of consent fees								109,000,000	$ 0	$ 0
Principal Issuances						54,750,000,000		54,750,000,000
Payments for third party bank fees								18,926,000,000	14,139,000,000	$ 13,161,000,000
Short-term debt						$ 4,579,000,000		$ 4,579,000,000	$ 25,000,000
Secured Bridge Loan Facility
Debt Instrument [Line Items]
Other			$ 71,000,000
6.500% Senior Notes due 2024
Debt Instrument [Line Items]
Interest rate, stated percentage						6.50%		6.50%
5.125% Senior Notes Due 2025
Debt Instrument [Line Items]
Interest rate, stated percentage						5.125%		5.125%
5.125% Senior Notes Due 2025 \| Affiliates
Debt Instrument [Line Items]
Interest rate, stated percentage		5.125%
6.375% Senior Notes due 2025
Debt Instrument [Line Items]
Interest rate, stated percentage						6.375%		6.375%
Incremental term loan facility to affiliates due 2022 \| Affiliates
Debt Instrument [Line Items]
Other								$ 0
Principal Amount				$ 2,000,000,000.0		$ 2,000,000,000		$ 2,000,000,000
Redemption Price (as a percent)								1.00%
Incremental term loan facility to affiliates due 2024 \| Affiliates
Debt Instrument [Line Items]
Other								$ 0
Principal Amount				2,000,000,000.0		$ 2,000,000,000		$ 2,000,000,000
Redemption Price (as a percent)								1.00%
5.300% Senior Notes due 2021 \| Affiliates
Debt Instrument [Line Items]
Interest rate, stated percentage						5.30%		5.30%
5.375% Senior Notes Due 2027
Debt Instrument [Line Items]
Interest rate, stated percentage						5.375%		5.375%
5.375% Senior Notes Due 2027 \| Affiliates
Debt Instrument [Line Items]
Interest rate, stated percentage						5.375%		5.375%
Spectrum Financing SPEs
Debt Instrument [Line Items]
Lease payments (per month)				165,000,000
Senior Notes
Debt Instrument [Line Items]
Principal Issuances			19,000,000,000.0								$ 4,750,000,000	$ 4,000,000,000.0		$ 4,000,000,000.0
Senior Notes \| 6.500% Senior Notes due 2024
Debt Instrument [Line Items]
Principal Amount		$ 1,000,000,000.0
Interest rate, stated percentage		6.50%				6.50%		6.50%
Redemption Price (as a percent)		102.167%						102.167%
Redemption premium		$ 22,000,000
Write-off of issuance costs		12,000,000
Senior Notes \| 5.125% Senior Notes due 2021 \| Affiliates
Debt Instrument [Line Items]
Principal Amount		$ 1,250,000,000
Interest rate, stated percentage		5.125%
Redemption Price (as a percent)		100.00%
Write-off of issuance costs		$ 15,000,000
Senior Notes \| 5.125% Senior Notes Due 2025 \| Affiliates
Debt Instrument [Line Items]
Interest rate, stated percentage						5.125%		5.125%
Redemption Price (as a percent)								100.00%
Senior Notes \| Senior Notes due 2020, 7.000%
Debt Instrument [Line Items]
Principal Amount													$ 1,500,000,000
Interest rate, stated percentage													7.00%
Senior Notes \| 6.375% Senior Notes due 2025
Debt Instrument [Line Items]
Principal Amount	$ 1,700,000,000
Interest rate, stated percentage	6.375%					6.375%		6.375%
Redemption Price (as a percent)	102.125%							102.125%
Write-off of issuance costs	$ 24,000,000
Senior Notes \| 5.300% Senior Notes due 2021 \| Affiliates
Debt Instrument [Line Items]
Interest rate, stated percentage						5.30%		5.30%
Redemption Price (as a percent)								100.00%
Senior Notes \| Senior Secured Series 2016-1 A-1 Notes due 2021, 3.360%
Debt Instrument [Line Items]
Other								$ 0
Principal Amount						$ 656,000,000		$ 656,000,000
Interest rate, stated percentage						3.36%		3.36%
Sprint
Debt Instrument [Line Items]
Principal Issuances						$ 24,605,000,000		$ 24,605,000,000
Notes issued and outstanding under Existing Sprint Spectrum Program (not exceed)					$ 7,000,000,000.0
Total outstanding obligation						4,600,000,000		4,600,000,000
Sprint \| Credit Facilities
Debt Instrument [Line Items]
Financing commitment, amount					$ 9,000,000,000.0
Secured indebtedness, limit, percentage					150.00%
Secured debt to cash flow					2.00
Sprint \| Secured Bridge Loan Facility
Debt Instrument [Line Items]
Financing commitment, amount			$ 19,000,000,000.0	19,000,000,000.0
Sprint \| Secured Term Loan Facility
Debt Instrument [Line Items]
Financing commitment, amount				$ 4,000,000,000.0
Sprint \| Senior Secured Series 2016-1 A-1 Notes due 2021, 3.360%
Debt Instrument [Line Items]
Interest rate, stated percentage				3.36%
Sprint \| Senior Secured Series 2018-1 A-1 Notes due 2025, 4.738%
Debt Instrument [Line Items]
Interest rate, stated percentage				4.738%
Short-term debt						394,000,000		394,000,000
Sprint \| Senior Secured Series 2018-1 A-2 Notes due 2028, 5.152%
Debt Instrument [Line Items]
Interest rate, stated percentage				5.152%
Sprint \| DT
Debt Instrument [Line Items]
Payments of consent fees							$ 7,000,000
Payments for requisite consents to DT				$ 13,000,000
Sprint \| DT \| Secured Term Loan Facility
Debt Instrument [Line Items]
Repayment of debt				4,000,000,000.0
Sprint \| Senior Notes
Debt Instrument [Line Items]
Payments for third party bank fees							6,000,000
Payments for requisite consents to third-party note holders				$ 95,000,000
Sprint \| Senior Notes \| Long-term debt
Debt Instrument [Line Items]
Payments of consent fees							17,000,000
Sprint \| Senior Notes \| Senior Notes due 2020, 7.000%
Debt Instrument [Line Items]
Interest rate, stated percentage				7.00%
Principal Issuances						0		0
Sprint \| Senior Notes \| Existing Sprint Spectrum Notes
Debt Instrument [Line Items]
Payments for requisite consents to third-party note holders				$ 41,000,000
Sprint \| Senior Notes \| Existing Sprint Spectrum Notes \| Long-term debt
Debt Instrument [Line Items]
Payments of consent fees							$ 14,000,000
Sprint \| Senior Notes \| Senior Secured Series 2016-1 A-1 Notes due 2021, 3.360%
Debt Instrument [Line Items]
Principal Issuances				3,500,000,000		656,000,000		656,000,000
Securitization program				$ 7,000,000,000.0
Payable term				5 years
Schedule principal repayments						656,000,000
Principal amount outstanding						656,000,000		656,000,000
Number of senior secured notes \| note															2
Sprint \| Senior Notes \| Senior Secured Series 2018-1 A-1 Notes due 2025, 4.738%
Debt Instrument [Line Items]
Principal Issuances						2,100,000,000		2,100,000,000
Sprint \| Senior Notes \| Senior Secured Series 2018-1 A-2 Notes due 2028, 5.152%
Debt Instrument [Line Items]
Principal Issuances				$ 1,800,000,000		$ 1,838,000,000		$ 1,838,000,000
Sprint \| Senior Notes \| DT \| Affiliates
Debt Instrument [Line Items]
Indebtedness to affiliates				$ 4,000,000,000.0
Sprint \| Senior Notes \| DT \| 5.125% Senior Notes Due 2025
Debt Instrument [Line Items]
Interest rate, stated percentage				5.125%
Principal Issuances				$ 1,250,000,000
Sprint \| Senior Notes \| DT \| 5.300% Senior Notes due 2021
Debt Instrument [Line Items]
Interest rate, stated percentage				5.30%
Principal Issuances				$ 2,000,000,000.0
Sprint \| Senior Notes \| DT \| 6.000% Senior Notes due 2024
Debt Instrument [Line Items]
Interest rate, stated percentage				6.00%
Principal Issuances				$ 2,000,000,000.0
Sprint \| Senior Notes \| DT \| 5.375% Senior Notes Due 2027
Debt Instrument [Line Items]
Interest rate, stated percentage				5.375%
Principal Issuances				$ 1,250,000,000
Sprint \| Senior Notes
Debt Instrument [Line Items]
Principal Issuances															$ 3,900,000,000