Acquisitions (Details) (USD $)	3 Months Ended		9 Months Ended				1 Months Ended		3 Months Ended	9 Months Ended							1 Months Ended	3 Months Ended	9 Months Ended							1 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Jul. 14, 2011	Mar. 31, 2011	Jul. 31, 2011 Senior notes	Jul. 31, 2011 Savvis	Sep. 30, 2012 Savvis	Sep. 30, 2012 Savvis	Jul. 15, 2011 Savvis	Jul. 15, 2011 Savvis Preliminary	Jul. 15, 2011 Savvis Preliminary Customer relationships	Jul. 15, 2011 Savvis Preliminary Other intangibles	Jul. 15, 2011 Savvis Restrospective adjustments Change in purchase price allocation	Jul. 15, 2011 Savvis Restrospective adjustments Customer relationships Change in purchase price allocation	Apr. 30, 2011 Qwest	Sep. 30, 2012 Qwest	Sep. 30, 2012 Qwest	Apr. 02, 2011 Qwest subscriber state accessline	Apr. 02, 2011 Qwest Customer relationships	Apr. 02, 2011 Qwest Capitalized software	Apr. 02, 2011 Qwest Other intangibles	Mar. 31, 2012 Qwest Restrospective adjustments Change in purchase price allocation	Mar. 31, 2012 Qwest Restrospective adjustments Customer relationships Change in purchase price allocation	Apr. 30, 2011 Qwest Restatement Change in purchase price allocation item
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
Cash payments											$ 1,732,000,000									$ 5,000,000
Common shares issued to consummate the merger								14,313,000									294,000,000
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
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 in which service is provided																				14
Long-term debt assumed in connection with acquisition																				12,700,000,000
Payments made towards retirement of existing Savvis debt and accrued interest								547,000,000
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												214,000,000								2,121,000,000
Property, plant and equipment												1,367,000,000			32,000,000					9,529,000,000				(25,000,000)
Intangible assets													739,000,000	51,000,000		55,000,000					7,558,000,000	1,702,000,000	189,000,000		(67,000,000)
Other noncurrent assets												27,000,000								390,000,000
Current liabilities, excluding current maturities of long-term debt												(129,000,000)								(2,426,000,000)
Current maturities of long-term debt												(38,000,000)								(2,422,000,000)
Long-term debt												(840,000,000)								(10,253,000,000)
Deferred credits and other liabilities												(358,000,000)			30,000,000					(4,238,000,000)				63,000,000
Number of lease valuations for which revisions were made																										1
Goodwill												1,349,000,000			(8,000,000)					10,123,000,000				17,000,000
Aggregate consideration											2,382,000,000									12,273,000,000
Fair value assigned to accounts receivable											90,000,000									1,194,000,000
Accounts receivable gross contractual value											101,000,000									1,274,000,000
Best estimate of contractual cash flows that would not be collected											11,000,000									80,000,000
Pro forma financial information
Acquisition related expenses								15,000,000
Operating revenues	4,571,000,000	4,633,000,000	13,793,000,000	14,039,000,000
Operating revenues									281,000,000	825,000,000								2,700,000,000	8,200,000,000
Net income	270,000,000	134,000,000	544,000,000	492,000,000
Basic earnings per common share (in dollars per share)	$ 0.43	$ 0.22	$ 0.87	$ 0.80
Diluted earnings per common share (in dollars per share)	$ 0.43	$ 0.22	$ 0.88	$ 0.80
Acquisition-related expenses	$ 17,000,000	$ 104,000,000	$ 68,000,000	$ 405,000,000