Acquisitions (Details) (USD $)	12 Months Ended					0 Months Ended	12 Months Ended			1 Months Ended	0 Months Ended	12 Months Ended		12 Months Ended	0 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jul. 14, 2011	Mar. 31, 2011	Jul. 15, 2011 Savvis	Dec. 31, 2013 Savvis	Dec. 31, 2011 Savvis	Dec. 31, 2012 Savvis	Jun. 30, 2011 Savvis Senior notes	Apr. 02, 2011 Qwest accessline subscriber state	Dec. 31, 2013 Qwest	Dec. 31, 2012 Qwest	Dec. 31, 2013 Appfog and Tier 3	Jan. 02, 2011 Qwest and Savvis acquisitions
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						0.2479					0.1664
Consideration transferred						$ 2,382,000,000					$ 12,273,000,000
Cash payments	160,000,000	0	0			1,732,000,000					5,000,000			160,000,000
Common shares issued to consummate the merger (shares)						14,313,000					294,008,925
Closing stock price used to value shares issued for acquisition (in dollars per share)				$ 38.54	$ 41.55
Estimated net value of pre-combination portion of share-based compensation awards assumed						98,000,000					52,000,000
Pre-combination portion of share-based compensation paid in cash						33,000,000
Payments made towards retirement of existing Savvis debt and accrued interest	2,010,000,000	5,118,000,000	2,984,000,000			547,000,000
Acquisition related expenses						15,000,000
Principal amount of senior notes issued to fund a portion of the acquisition and refinance Savvis' existing debt										2,000,000,000
Number of access lines served by acquiree entity (access lines)											9,000,000
Number of broadband subscribers served by acquiree entity (subscribers)											3,000,000
Number of states in which service is provided (states)											14
Long-term debt assumed in connection with acquisition											12,700,000,000
Goodwill	20,674,000,000	21,627,000,000				1,335,000,000					10,032,000,000			139,000,000
Acquisition-related expenses	53,000,000	83,000,000	467,000,000
Merger-related transaction costs, cumulative amount									62,000,000				511,000,000
Transaction expenses incurred in connection with terminating an unused loan financing commitment related to acquisition								16,000,000
Merger-related pre-acquisition costs							22,000,000					71,000,000
Merger-related pre-acquisition costs, prior to acquisition							3,000,000					36,000,000
Merger-related pre-acquisition costs, on the date of acquisition							19,000,000					35,000,000
Pro forma financial information
Operating revenues															18,692,000,000
Net income															$ 601,000,000
Basic earnings per common share (usd per share)															$ 0.97
Diluted earnings per common share (usd per share)															$ 0.97