Severance and Leased Real Estate (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2012 Y	Dec. 31, 2011
Severance
Restructuring reserve
Balance at the beginning of the period	$ 37
Accrued to expense	57
Payments, net	(29)
Reversals and adjustments	(3)
Balance at the end of the period	62
Real estate
Restructuring reserve
Balance at the beginning of the period	153
Accrued to expense	1
Payments, net	(4)
Balance at the end of the period	150
Current portion of leased real estate accrual	30	27
Noncurrent portions of leased real estate accrual	$ 120	$ 126
Weighted average lease terms (in years)	9.3
Real estate \| Minimum
Restructuring reserve
Remaining lease terms (in years)	0.1
Real estate \| Maximum
Restructuring reserve
Remaining lease terms (in years)	13.8

Represents the current portion of leased real estate accrual on the balance sheet date.

No definition available.

Name:	ctl_LeasedAssetCurrent
Namespace Prefix:	ctl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the long-term portion of leased real estate accrual on the balance sheet date.

+ References

No definition available.

+ Details

Name:	ctl_LeasedAssetNoncurrent
Namespace Prefix:	ctl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the remaining lease term recorded upon the acquisition date.

+ References

No definition available.

+ Details

Name:	ctl_LeaseTerm
Namespace Prefix:	ctl_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the amount of foreign currency translation adjustment and other reversals increasing or decreasing for a specified type of restructuring cost.

+ References

No definition available.

+ Details

Name:	ctl_RestructuringReserveReversalsAndAdjustment
Namespace Prefix:	ctl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Weighted average term of remaining leases assumed in connection with an acquisition.

+ References

No definition available.

+ Details

Name:	ctl_WeightedAverageLeaseTerm
Namespace Prefix:	ctl_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

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

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number 95-3

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section P

-Subsection 3, 4

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SAB TOPIC 5.P.4(b))

-URI http://asc.fasb.org/extlink&oid=6394695&loc=d3e140904-122747

+ Details

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

- Definition

Reserve increase representing the amount charged against earnings in the period for a specified incurred and estimated type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 146

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)(2)

-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

+ Details

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

- Details

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

- Definition

Amount of cash paid in the period to fully or partially settle a specified, previously accrued type of restructuring cost.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SAB TOPIC 5.P.4(b)(2))

-URI http://asc.fasb.org/extlink&oid=6394695&loc=d3e140904-122747

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b) (2)

-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number 95-3

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section P

-Subsection 3, 4

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 146

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

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