Repurchase of CenturyLink Common Stock (Details) - Share repurchase program authorized February 2014 - USD ($) $ / shares in Units, shares in Millions, $ in Millions		1 Months Ended	9 Months Ended	17 Months Ended
	Oct. 05, 2015	Feb. 27, 2014	Sep. 30, 2015	Nov. 03, 2015	Feb. 28, 2014
Schedule of Stock Repurchased and Retired
Stock repurchase program, period in force		24 months
Stock repurchases, aggregate authorized amount					$ 1,000
Number of shares repurchased and retired (shares)			16.8
Aggregate market price of shares repurchased			$ 523
Average purchase price at which shares were repurchased (in dollars per share)			$ 31.08
Stock repurchases, remaining authorized amount			$ 278
Subsequent Event [Member]
Schedule of Stock Repurchased and Retired
Number of shares repurchased and retired (shares)				27.5
Aggregate market price of shares repurchased	$ 18			$ 866
Average purchase price at which shares were repurchased (in dollars per share)	$ 24.86			$ 31.52