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

No definition available.

Name:	ctl_NumberOfCategoriesOfProductsAndServices
Namespace Prefix:	ctl_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of markets.

+ References

No definition available.

+ Details

Name:	ctl_NumberofMarkets
Namespace Prefix:	ctl_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- 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

Name:	ctl_UniversalServiceTaxesAndSurcharges
Namespace Prefix:	ctl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- 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=63488584&loc=d3e20235-122688

+ Details

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

- Definition

Disclosure of the extent of enterprise reliance on its major customers. For example, includes revenues from transactions with a single external customer amounting to 10 percent or more of the entity's revenues, the total amount of revenues from each such customer, and the identity of the segment or segments reporting the revenues. A group of entities that the entity knows to be under common control generally will be considered a single customer for inclusion in this item. The federal government, a state government, a local government (for example, a county or municipality), or a foreign government each will generally be considered as a single customer for inclusion in this item.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 42
-URI http://asc.fasb.org/extlink&oid=68060357&loc=d3e9054-108599

+ Details

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

Segment Information (Details 2) $ in Millions	3 Months Ended		9 Months Ended
Segment Information (Details 2) $ in Millions	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) category	Sep. 30, 2015 USD ($)
Operating revenues by products and services
Number of categories of products and services (categories) \| category			4
Revenues	$ 4,382	$ 4,554	$ 13,181	$ 13,424
Surcharge amount on customers' bills	144	137	$ 435	411
Individual customers accounting for more than 10% of total operating revenues			We do not have any single customer that provides more than 10% of our total consolidated operating revenues.
Strategic services
Operating revenues by products and services
Revenues	$ 2,015	1,929	$ 6,034	5,761
Facilities-based video services
Operating revenues by products and services
Number of markets	16		16
Legacy services
Operating revenues by products and services
Revenues	$ 1,900	2,062	$ 5,826	6,302
Data integration
Operating revenues by products and services
Revenues	163	154	402	437
Other revenues
Operating revenues by products and services
Revenues	304	409	919	924
High cost support revenue
Operating revenues by products and services
Revenues	171	284	518	550
Other revenue
Operating revenues by products and services
Revenues	133	125	401	374
Business
Operating revenues by products and services
Revenues	2,606	2,636	7,807	7,991
Business \| Business high-bandwidth data services
Operating revenues by products and services
Revenues	744	699	2,235	2,083
Business \| Business hosting services
Operating revenues by products and services
Revenues	303	324	915	961
Business \| Other business strategic services
Operating revenues by products and services
Revenues	179	143	521	458
Business \| Voice services
Operating revenues by products and services
Revenues	601	638	1,834	1,956
Business \| Business low-bandwidth data services
Operating revenues by products and services
Revenues	339	391	1,057	1,213
Business \| Other business legacy services
Operating revenues by products and services
Revenues	277	288	844	885
Business \| Data integration
Operating revenues by products and services
Revenues	163	153	401	435
Consumer
Operating revenues by products and services
Revenues	1,472	1,509	4,455	4,509
Consumer \| Consumer broadband services
Operating revenues by products and services
Revenues	674	658	2,023	1,945
Consumer \| Other consumer strategic services
Operating revenues by products and services
Revenues	115	105	340	314
Consumer \| Voice services
Operating revenues by products and services
Revenues	605	664	1,854	2,027
Consumer \| Other consumer legacy services
Operating revenues by products and services
Revenues	78	81	237	221
Consumer \| Data integration
Operating revenues by products and services
Revenues	$ 0	1	$ 1	2
Business low-bandwidth data services \| Restatement adjustment \| Business \| Strategic services
Operating revenues by products and services
Revenues		(389)		(1,207)
Business low-bandwidth data services \| Restatement adjustment \| Business \| Legacy services
Operating revenues by products and services
Revenues		389		1,207
Other business strategic services \| Restatement adjustment \| Business \| Strategic services
Operating revenues by products and services
Revenues		2		6
Other business legacy services \| Restatement adjustment \| Business \| Legacy services
Operating revenues by products and services
Revenues		$ (2)		$ (6)