Long-Term Debt - Supplier Finance Program, Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Debt Disclosure [Abstract]
Period of installment payments	5 years
Annual interest on unpaid balances (as a percent)	1.25%
Credits	$ 24	$ 15
Current obligations	$ 21	$ 16
Supplier Finance Program, Obligation, Current, Statement of Financial Position [Extensible Enumeration]	Current maturities of long-term debt	Current maturities of long-term debt
Noncurrent obligations	$ 18	$ 39
Supplier Finance Program, Obligation, Noncurrent, Statement of Financial Position [Extensible Enumeration]	LONG-TERM DEBT	LONG-TERM DEBT

Supplier Finance Program, Annual Interest On Unpaid Balances

No definition available.

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Balance Type:	na
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- Definition

Supplier Finance Program, Credit

+ References

No definition available.

+ Details

Name:	lumn_SupplierFinanceProgramCredit
Namespace Prefix:	lumn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
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- Definition

Amount of obligation for supplier finance program, classified as current.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479468/405-50-50-3

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479468/405-50-50-3

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479468/405-50-50-4

+ Details

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

- Definition

Indicates line item in statement of financial position that includes obligation for supplier finance program, classified as current.

+ References

+ Details

Name:	us-gaap_SupplierFinanceProgramObligationCurrentStatementOfFinancialPositionExtensibleEnumeration
Namespace Prefix:	us-gaap_
Data Type:	enum2:enumerationSetItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of obligation for supplier finance program, classified as noncurrent.

+ References

+ Details

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

- Definition

Indicates line item in statement of financial position that includes obligation for supplier finance program, classified as noncurrent.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	enum2:enumerationSetItemType
Balance Type:	na
Period Type:	instant

- Definition

Period when payment is expected to be made to finance provider or intermediary in supplier finance program, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 405
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479468/405-50-50-3

+ Details

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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant