Acquisitions (Details) (USD $)	3 Months Ended		1 Months Ended	3 Months Ended									1 Months Ended	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Apr. 30, 2011 Qwest	Mar. 31, 2012 Qwest	Dec. 31, 2011 Qwest	Apr. 02, 2011 Qwest accessline subscriber state	Mar. 31, 2011 Qwest	Apr. 02, 2011 Qwest Customer relationships	Apr. 02, 2011 Qwest Capitalized software	Apr. 02, 2011 Qwest Other intangibles	Apr. 02, 2011 Qwest Changes in estimates	Apr. 02, 2011 Qwest Changes in estimates Customer relationships	Jul. 31, 2011 Savvis	Mar. 31, 2012 Savvis	Jul. 15, 2011 Savvis	Jul. 14, 2011 Savvis	Jul. 15, 2011 Savvis Customer relationships	Jul. 15, 2011 Savvis Other intangibles	Jul. 15, 2011 Savvis Changes in estimates	Jul. 15, 2011 Savvis Changes in estimates Customer relationships
Acquisitions
Share price of CenturyLink shares that Savvis shareholders received for each share of common stock owned at closing (in dollars per share)															$ 30
Number of CenturyLink shares that shareholders received for each share of common stock owned at closing						0.1664									0.2479
Cash payments to Savvis shareholders															$ 1,732,000,000
Common shares issued to consummate the merger			294,000,000										14,313,000
Value of common shares issued (in dollars per share)							$ 41.55									$ 38.54
Closing stock price used to value shares issued for acquisition (in dollars per share)															$ 98,000,000
Estimated net value of pre-combination portion of share-based compensation awards assumed by CenturyLink						52,000,000
Pre-combination portion of share-based compensation paid in cash													33,000,000
Number of access lines served by acquiree entity						9,000,000
Number of broadband subscribers served by acquiree entity						3,000,000
Number of states served by acquiree entity						14
Cash paid in lieu of fractional shares						5,000,000
Long-term debt assumed in connection with acquisition				12,700,000,000
Principal amount of senior notes issued to fund a portion of the acquisition and refinance Savvis' existing debt													2,000,000,000
Assignment of the aggregate consideration
Cash, accounts receivable and other current assets						2,121,000,000									214,000,000
Property, plant and equipment						9,529,000,000					(25,000,000)				1,377,000,000				42,000,000
Intangible assets								7,558,000,000	1,702,000,000	189,000,000		(67,000,000)					739,000,000	51,000,000		(55,000,000)
Other noncurrent assets						390,000,000									27,000,000
Current liabilities, excluding current maturities of long-term debt						(2,426,000,000)									(129,000,000)
Current maturities of long-term debt						(2,422,000,000)									(38,000,000)
Long-term debt						(10,253,000,000)									(840,000,000)
Deferred credits and other liabilities						(4,238,000,000)					63,000,000				(362,000,000)				26,000,000
Goodwill						10,123,000,000					17,000,000				1,343,000,000				(14,000,000)
Aggregate consideration						12,273,000,000									2,382,000,000
Fair value assigned to accounts receivable						1,194,000,000
Accounts receivable gross contractual value						1,274,000,000
Best estimate of contractual cash flows that would not be collected						80,000,000
Pro forma financial information
OPERATING REVENUES	4,610,000,000	1,696,000,000
Operating revenues				2,700,000,000										266,000,000
Operating revenues		4,737,000,000
Net income	200,000,000	211,000,000
Net income		275,000,000
Basic earnings per common share	$ 0.32	$ 0.69
Basic earnings per common share (in dollars per share)		$ 0.45
Diluted earnings per common share	$ 0.32	$ 0.69
Diluted earnings per common share (in dollars per share)		$ 0.44
Merger-related transaction costs, cumulative amount				$ 39,000,000	$ 35,000,000										$ 15,000,000