Document and Entity Information In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jul. 16, 2012
Document and Entity Information
Document Type	10-Q
Document Period End Date	Jun. 30, 2012
Document Fiscal Year Focus	2012
Amendment Flag	false
Document Fiscal Period Focus	Q2
Entity Registrant Name	NCR CORP
Entity Central Index Key	0000070866
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		159.1
Current Fiscal Year End Date	--12-31