Cover - USD ($) shares in Millions, $ in Billions	12 Months Ended
	Dec. 31, 2021	Jan. 31, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Document Transition Report	false
Entity File Number	001-33458
Entity Registrant Name	TERADATA CORPORATION
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	75-3236470
Entity Address, Address Line One	17095 Via Del Campo
Entity Address, City or Town	San Diego
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92127
City Area Code	866
Local Phone Number	548-8348
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	TDC
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 5.4
Entity Common Stock, Shares Outstanding (in shares)		106.1
Documents Incorporated by Reference	Portions of the registrant’s Notice of Annual Meeting of Stockholders and Proxy Statement, to be filed with the Securities and Exchange Commission pursuant to Regulation 14A within 120 days after registrant’s fiscal year end of December 31, 2021 are incorporated herein by reference.
Entity Central Index Key	0000816761
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Amendment Flag	false