Segment Information (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015 category	Mar. 31, 2014
Operating revenues by products and services
Number of groups of products and services (categories)	4ctl_NumberOfGroupsOfProductsAndServices
OPERATING REVENUES	$ 4,451us-gaap_Revenues	$ 4,538us-gaap_Revenues
Surcharge amount on customers' bills	135ctl_UniversalServiceTaxesAndSurcharges	131ctl_UniversalServiceTaxesAndSurcharges
Strategic services
Operating revenues by products and services
Products and services categories reclassification adjustment		(10)
OPERATING REVENUES	2,320	2,271
Legacy services
Operating revenues by products and services
Products and services categories reclassification adjustment		10
OPERATING REVENUES	1,735	1,839
Data integration
Operating revenues by products and services
OPERATING REVENUES	139	174
Other
Operating revenues by products and services
OPERATING REVENUES	$ 257	$ 254

Represents the number of groups of products and services of the reporting entity.

No definition available.

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- Definition

The amount of a reclassification adjustment made to prior period products and services categories amounts.

+ References

No definition available.

+ Details

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- Definition

Amount of the universal taxes and surcharges that are reflected in the statement of income (included in both operating revenues and expenses).

+ References

No definition available.

+ Details

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- Details

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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

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- Details

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- Details

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- Details

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