Products and Services Revenues (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015 segment category	Mar. 31, 2014
Products and Services Revenues
Number of categories of products and services (categories)	3
Total operating revenues	$ 2,217us-gaap_Revenues	$ 2,211us-gaap_Revenues
USF surcharges and transaction taxes included in operating revenues and expenses	37	39
Number of reportable segments (segments)	1us-gaap_NumberOfReportableSegments
Strategic services
Products and Services Revenues
Total operating revenues	857	856
Legacy services
Products and Services Revenues
Total operating revenues	712	767
Affiliates and other services
Products and Services Revenues
Total operating revenues	$ 648	$ 588

Represents the number of categories in which the entity categorizes the products and services.

No definition available.

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- Definition

Represents the taxes and surcharges on revenues from universal service funds (USF), which are included in operating revenues and expenses.

+ References

No definition available.

+ Details

Name:	ctq_UniversalServiceFundsTaxesAndSurcharges
Namespace Prefix:	ctq_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems
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Balance Type:	na
Period Type:	duration

- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
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- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

+ Details

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Period Type:	duration

- Details

Name:	us-gaap_ProductOrServiceAxis=ctq_AffiliatesAndOtherServicesMember
Namespace Prefix:
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- Details

Name:	us-gaap_ProductOrServiceAxis=ctq_LegacyServicesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=ctq_StrategicServicesMember
Namespace Prefix:
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Balance Type:
Period Type: