Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Nov. 12, 2018
Document and Entity Information
Entity Registrant Name	QWEST CORP
Entity Central Index Key	0000068622
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Small Business	false
Entity Emerging Growth	false
Entity Common Stock, Shares Outstanding		1