Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Nov. 01, 2014
Entity Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2014
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	Q3
Trading Symbol	CONE
Entity Registrant Name	CyrusOne Inc.
Entity Central Index Key	0001553023
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		38,653,028
CyrusOne LP [Member]
Entity Information [Line Items]
Entity Registrant Name	CyrusOne LP
Entity Central Index Key	0001575810
Entity Filer Category	Non-accelerated Filer