Document and Entity Information	6 Months Ended
	Jun. 30, 2013	Jul. 26, 2013
Document Information
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q2
Trading Symbol	TDC
Entity Registrant Name	TERADATA CORP /DE/
Entity Central Index Key	0000816761
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		163,100,000