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Employee Stock-based Compensation Plans - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized to be issued under the Teradata SIP (in shares)	17,500,000
Weighted-average fair value of options granted for Teradata equity awards (in usd per share)	$ 0	$ 0	$ 11.08
Employee Stock Purchase Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock purchase program discount from average market price (as a percentage)	15.00%
Percentage of authorized payroll deductions for common stock purchases by employees (as a percentage)	10.00%
Shares authorized to be issued under the Employee Stock Purchase Program (in shares)	7,000,000
Remaining shares authorized to be issued under the Employee Stock Purchase Program (in shares)	2,100,000
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option, term (in years)	10 years
Vesting period (in years)	4 years
Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost related to unvested stock grants	$ 2
Cost expected to be recognized over a weighted-average period (in years)	6 months
Service-Based Awards \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	3 years
Performance Based Awards \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	1 year
Performance Based Awards \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	3 years
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost related to unvested stock grants	$ 137
Cost expected to be recognized over a weighted-average period (in years)	1 year 1 month 6 days
Special 2016 PSRSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period	3 years
Special 2016 PSRSU \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance share percentage	0.00%
Special 2016 PSRSU \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance share percentage	200.00%