Name:	ctl_ScheduleofStockRepurchasesLineItems
Namespace Prefix:	ctl_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Value of stock repurchased and retired divided by the number of shares repurchased and retired.

+ References

No definition available.

+ Details

Name:	ctl_StockRepurchasedandRetiredDuringPeriodAverageCostperShare
Namespace Prefix:	ctl_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The average cost per share of the stock that has been repurchased and retired during the program period.

+ References

No definition available.

+ Details

Name:	ctl_StockRepurchasedandRetiredDuringProgramPeriodAverageCostperShare
Namespace Prefix:	ctl_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Total number of shares that have been repurchased and retired during the program period.

+ References

No definition available.

+ Details

Name:	ctl_StockRepurchasedandRetiredDuringProgramPeriodShares
Namespace Prefix:	ctl_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The value of stock repurchased and retired during stock repurchase program.

+ References

No definition available.

+ Details

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

- Definition

Number of shares that have been repurchased and retired during the period.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29, 30

-Article 5

+ Details

Name:	us-gaap_StockRepurchasedAndRetiredDuringPeriodShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital).

+ References

+ Details

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

- Definition

Amount of stock repurchase plan authorized.

+ References

No definition available.

+ Details

Name:	us-gaap_StockRepurchaseProgramAuthorizedAmount1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Period which shares may be purchased under a stock repurchase plan authorized by an entity's Board of Directors, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_StockRepurchaseProgramPeriodInForce1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount remaining of a stock repurchase plan authorized.

+ References

No definition available.

+ Details

Name:	us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Repurchase of CenturyLink Common Stock (Details) (Share repurchase program authorized February 2014, USD $) Share data in Millions, except Per Share data, unless otherwise specified	1 Months Ended	3 Months Ended	11 Months Ended
	Feb. 27, 2014	Mar. 31, 2015	May 04, 2015	Feb. 28, 2014
Schedule of Stock Repurchases
Stock repurchase program, period in force	24 months
Stock repurchases, aggregate authorized amount				$ 1,000,000,000
Number of shares repurchased (shares)		4.5
Aggregate market price of shares repurchased		170,000,000
Average purchase price at which shares were repurchased (in dollars per share)		$ 37.53
Stock repurchases, remaining authorized amount		630,000,000
Subsequent Event [Member]
Schedule of Stock Repurchases
Stock repurchased and retired during program period (shares)			11.7
Stock repurchased and retired during program period, Value			$ 439,000,000
Stock repurchased and retired during program period, average cost per share (in dollars per share)			$ 0