Cover Page - shares	3 Months Ended
	Mar. 31, 2020	May 04, 2020
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2020
Document Transition Report	false
Entity File Number	001-7784
Entity Registrant Name	CENTURYLINK, INC.
Entity Incorporation, State or Country Code	LA
Entity Tax Identification Number	72-0651161
Entity Address, Address Line One	100 CenturyLink Drive,
Entity Address, City or Town	Monroe,
Entity Address, State or Province	LA
Entity Address, Postal Zip Code	71203
City Area Code	318
Local Phone Number	388-9000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		1,097,502,122
Entity Central Index Key	0000018926
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
COMMON STOCK
Document Information [Line Items]
Title of 12(b) Security	Common Stock, par value $1.00 per share
Trading Symbol	CTL
Security Exchange Name	NYSE
PREFERRED STOCK
Document Information [Line Items]
Title of 12(b) Security	Preferred Stock Purchase Rights
No Trading Symbol Flag	true
Security Exchange Name	NYSE