Stock Repurchased and Retired During Period, Average Cost Per Share

No definition available.

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Namespace Prefix:	tmus_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

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-Topic 835
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+ Details

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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

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-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22)(a)(1))
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

+ References

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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-SubTopic 10
-Topic 505
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+ Details

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

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
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Period Type:	duration

- Details

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- Details

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Period Type:

- Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=tmus_A5.000SeniorNotesDue2036Member
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Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=tmus_A5.850SeniorNotesDue2056Member
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Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=tmus_A4.750SeniorNotesDue2028Member
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Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_NotesPayableOtherPayablesMember
Namespace Prefix:
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Period Type:

Subsequent Events (Details) - USD ($)	1 Months Ended	12 Months Ended
Subsequent Events (Details) - USD ($)	Feb. 06, 2026	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Feb. 05, 2026	Jan. 22, 2026	Jan. 12, 2026
Subsequent Event [Line Items]
Principal outstanding		$ 13,827,000,000
Debt instrument, repurchased face amount		1,199,000,000
Purchase price		9,957,000,000	$ 11,206,000,000	$ 13,255,000,000
Senior Notes
Subsequent Event [Line Items]
Principal outstanding		$ 10,827,000,000
Subsequent Event \| 2026 Stockholder Return Program
Subsequent Event [Line Items]
Repurchases of common stock (in shares)	5,106,691
Average price paid per share (in USD per share)	$ 192.61
Purchase price	$ 984,000,000
5.000% Senior Notes due 2036 \| Subsequent Event
Subsequent Event [Line Items]
Principal outstanding							$ 1,200,000,000
Interest rate, stated percentage							5.00%
5.850% Senior Notes due 2056 \| Subsequent Event
Subsequent Event [Line Items]
Principal outstanding							$ 850,000,000
Interest rate, stated percentage							5.85%
4.750% Senior Notes due 2028 \| Senior Notes
Subsequent Event [Line Items]
Interest rate, stated percentage		4.75%
4.750% Senior Notes due 2028 \| Subsequent Event \| Senior Notes
Subsequent Event [Line Items]
Interest rate, stated percentage						4.75%
Debt instrument, repurchased face amount						$ 3,000,000,000
Notes Payable, Other Payables \| Subsequent Event
Subsequent Event [Line Items]
Principal outstanding					$ 1,000,000,000