Repurchase of CenturyLink Common Stock (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	12 Months Ended	16 Months Ended	9 Months Ended
	Dec. 31, 2014	May 31, 2014	Feb. 20, 2015	Feb. 28, 2013	Feb. 28, 2014
Share Repurchase Program Authorized February 2013 [Member]
Schedule of Stock Repurchases [Line Items]
Stock repurchases, aggregate authorized amount				$ 2,000,000,000
Stock repurchased and retired during program period (shares)		59.5
Stock repurchased and retired during program period, average cost per share	$ 33.63
Stock repurchased and retired during period, shares	13.7
Stock repurchased and retired during period, value	433,000,000
Stock repurchased and retired during period, average cost per share	$ 31.54
Share Repurchase Program Authorized February 2014 [Member]
Schedule of Stock Repurchases [Line Items]
Stock repurchases, aggregate authorized amount					1,000,000,000
Stock repurchased and retired during period, shares	5.2
Stock repurchased and retired during period, value	200,000,000
Stock repurchased and retired during period, average cost per share	$ 38.40
Stock repurchase program shares unsettled amount	6,000,000
Stock repurchase program shares unsettled average cost per share	$ 40.22
Stock repurchase program, period in force	24 months
Stock repurchases, remaining authorized amount	800,000,000
Subsequent Event | Share Repurchase Program Authorized February 2014 [Member]
Schedule of Stock Repurchases [Line Items]
Stock repurchased and retired during program period (shares)			7.7
Stock repurchased and retired during program period, value			$ 298,000,000
Stock repurchased and retired during program period, average cost per share			$ 38.57