Amount authorized for purchase of share under share repurchase plan. Includes, but is not limited to, repurchase of stock and unit of ownership.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 505
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481520/505-30-50-4

+ Details

Name:	srt_StockRepurchaseProgramAuthorizedAmount1
Namespace Prefix:	srt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Equipment Installment Plan, Payment Term

+ References

No definition available.

+ Details

Name:	tmus_EquipmentInstallmentPlanPaymentTerm
Namespace Prefix:	tmus_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Equipment Installment Plan Receivable Initial Term

+ References

No definition available.

+ Details

Name:	tmus_EquipmentInstallmentPlanReceivableInitialTerm
Namespace Prefix:	tmus_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Financing Option, Devices and Accessories, Payment Period

+ References

No definition available.

+ Details

Name:	tmus_FinancingOptionDevicesAndAccessoriesPaymentPeriod
Namespace Prefix:	tmus_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Financing Options, Devices and Accessories, Interest, Percent

+ References

No definition available.

+ Details

Name:	tmus_FinancingOptionsDevicesAndAccessoriesInterestPercent
Namespace Prefix:	tmus_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Licenses Issued, Fixed Period

+ References

No definition available.

+ Details

Name:	tmus_LicensesIssuedFixedPeriod
Namespace Prefix:	tmus_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Spectrum Leasing, Lease Term

+ References

No definition available.

+ Details

Name:	tmus_SpectrumLeasingLeaseTerm
Namespace Prefix:	tmus_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Spectrum Leasing, Total Lease Term

+ References

No definition available.

+ Details

Name:	tmus_SpectrumLeasingTotalLeaseTerm
Namespace Prefix:	tmus_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Term of Contract

+ References

No definition available.

+ Details

Name:	tmus_TermOfContract
Namespace Prefix:	tmus_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 720
-SubTopic 35
-Name Accounting Standards Codification
-Section 55
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483385/720-35-55-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 720
-SubTopic 35
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483406/720-35-50-1

+ Details

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

- Definition

Amortization period of cost capitalized in obtaining or fulfilling contract with customer, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-SubTopic 40
-Topic 340
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479483/340-40-50-2

+ Details

Name:	us-gaap_CapitalizedContractCostAmortizationPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- 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://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-SubTopic 10
-Topic 210
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-4

+ Details

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

- Definition

The amount of excise and sales taxes included in sales and revenues, which are then deducted as a cost of sales. Includes excise taxes, which are applied to specific types of transactions or items (such as gasoline or alcohol); and sales, use and value added taxes, which are applied to a broad class of revenue-producing transactions involving a wide range of goods and services.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

+ Details

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

- 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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 9
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-9

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 9
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-9

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 9
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-9

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 9
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-9

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 9
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-9

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 17
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480336/718-10-65-17

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 17
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480336/718-10-65-17

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 17
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480336/718-10-65-17

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 17
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480336/718-10-65-17

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476173/280-10-65-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476173/280-10-65-1

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-1

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 9
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482615/740-10-65-9

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 9
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482615/740-10-65-9

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 9
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482615/740-10-65-9

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 7
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-7

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 60
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476176/805-60-65-1

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 60
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476176/805-60-65-1

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 60
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476176/805-60-65-1

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 60
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476176/805-60-65-1

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 60
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476176/805-60-65-1

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480016/944-40-65-2

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 29: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 32: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 33: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 34: http://www.xbrl.org/2003/role/disclosureRef
-Topic 848
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (a)(3)(iii)(03)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483550/848-10-65-2

Reference 35: http://www.xbrl.org/2003/role/disclosureRef
-Topic 848
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (a)(3)(iii)(01)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483550/848-10-65-2

Reference 36: http://www.xbrl.org/2003/role/disclosureRef
-Topic 848
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483550/848-10-65-2

Reference 37: http://www.xbrl.org/2003/role/disclosureRef
-Topic 848
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483550/848-10-65-2

Reference 38: http://www.xbrl.org/2003/role/disclosureRef
-Topic 848
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483550/848-10-65-2

Reference 39: http://www.xbrl.org/2003/role/disclosureRef
-Topic 848
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483550/848-10-65-1

Reference 40: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 8
-Subparagraph (c)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479832/842-10-65-8

Reference 41: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 8
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479832/842-10-65-8

Reference 42: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
-SubTopic 50
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477123/405-50-65-1

Reference 43: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 13
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482477/820-10-65-13

Reference 44: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482477/820-10-65-13

Reference 45: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 5
-Subparagraph (c)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479654/326-10-65-5

Reference 46: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480528/815-20-65-6

Reference 47: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480528/815-20-65-6

Reference 48: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480528/815-20-65-6

Reference 49: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480528/815-20-65-6

Reference 50: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (h)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480528/815-20-65-6

Reference 51: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (h)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480528/815-20-65-6

Reference 52: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (h)(1)(iii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480528/815-20-65-6

Reference 53: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (h)(1)(iv)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480528/815-20-65-6

Reference 54: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (i)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480528/815-20-65-6

Reference 55: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (i)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480528/815-20-65-6

Reference 56: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479845/805-20-65-3

Reference 57: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479845/805-20-65-3

Reference 58: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 3
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479845/805-20-65-3

Reference 59: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-6

Reference 60: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-6

Reference 61: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-6

Reference 62: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-6

Reference 63: http://www.xbrl.org/2003/role/disclosureRef
-Topic 105
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 6
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479343/105-10-65-6

Reference 64: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480016/944-40-65-2

Reference 65: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480016/944-40-65-2

Reference 66: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480016/944-40-65-2

Reference 67: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (f)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480016/944-40-65-2

Reference 68: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (f)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480016/944-40-65-2

Reference 69: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480016/944-40-65-2

Reference 70: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480016/944-40-65-2

Reference 71: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(iii)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480016/944-40-65-2

Reference 72: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(iv)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480016/944-40-65-2

Reference 73: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (h)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480016/944-40-65-2

Reference 74: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (h)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480016/944-40-65-2

Reference 75: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 5
-Subparagraph (SAB Topic 11.M.Q2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480530/250-10-S99-5

Reference 76: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 8
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482615/740-10-65-8

Reference 77: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 8
-Subparagraph (d)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482615/740-10-65-8

Reference 78: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479654/326-10-65-4

Reference 79: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (e)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479654/326-10-65-4

Reference 80: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 10
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (e)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479654/326-10-65-4

Reference 81: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-3

Reference 82: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-1

Reference 83: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-1

Reference 84: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482635/260-10-55-15

Reference 85: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483421/250-10-45-6

Reference 86: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480175/815-40-65-1

Reference 87: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480175/815-40-65-1

Reference 88: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480175/815-40-65-1

Reference 89: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480175/815-40-65-1

Reference 90: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480175/815-40-65-1

Reference 91: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480175/815-40-65-1

Reference 92: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480175/815-40-65-1

Reference 93: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480175/815-40-65-1

Reference 94: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480175/815-40-65-1

Reference 95: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (e)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480175/815-40-65-1

Reference 96: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480175/815-40-65-1

Reference 97: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480424/946-10-50-3

Reference 98: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 60
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476166/350-60-65-1

Reference 99: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (f)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481538/470-20-65-4

Reference 100: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (f)(4)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481538/470-20-65-4

Reference 101: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 60
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476166/350-60-65-1

Reference 102: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476151/220-40-65-1

Reference 103: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481538/470-20-65-4

Reference 104: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 65
-Paragraph 4
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481538/470-20-65-4

Reference 105: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476151/220-40-65-1

Reference 106: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476151/220-40-65-1

+ Details

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

- Details

Name:	srt_ShareRepurchaseProgramAxis=tmus_A2022StockRepurchaseProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ShareRepurchaseProgramAxis=tmus_A20232024StockholderReturnProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ShareRepurchaseProgramAxis=tmus_A2025StockholderReturnProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ShareRepurchaseProgramAxis=tmus_A2026StockholderReturnProgramMember
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_IndefiniteLivedIntangibleAssetsByMajorClassAxis=tmus_SpectrumLicensesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TransactionTypeAxis=tmus_EIPSecuritizationArrangementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Summary of Significant Accounting Policies (Details) $ in Millions, € in Billions	12 Months Ended
	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2025 EUR (€)	Dec. 11, 2025 USD ($)	Dec. 13, 2024 USD ($)	Sep. 06, 2023 USD ($)	Sep. 08, 2022 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
EIP receivables initial term	36 months
Other finance liabilities \| €				€ 4.8
Term of contract	1 month
Federal Universal Service Fund and other fees	$ 400	$ 386	$ 317
Financing option, devices and accessories, interest rate (percent)	0.00%
Financing option, devices and accessories, payment period	24 months
Average amortization period, deferred contract costs (in months)				24 months
Advertising expense	$ 3,700	$ 3,100	$ 2,500
2022 Stock Repurchase Program
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stock repurchase program, authorized amount								$ 14,000
2023-2024 Stockholder Return Program
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stock repurchase program, authorized amount							$ 19,000
2025 Stockholder Return Program
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stock repurchase program, authorized amount						$ 14,000
2026 Stockholder Return Program
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stock repurchase program, authorized amount					$ 14,600
Sprint
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total term of agreement	30 years
Sprint \| Spectrum Licenses
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Fixed period	15 years
Minimum \| Sprint
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Agreements with educational and certain non-profit institutions, term	5 years
Minimum \| EIP Securitization Arrangement
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Equipment installment plan, maximum payment term	24 months
Maximum \| Sprint
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Agreements with educational and certain non-profit institutions, term	10 years