Debt	9 Months Ended
Debt	Sep. 30, 2019
Debt Disclosure [Abstract]
Debt	Debt In June 2018, Teradata replaced an existing five-year, $400 million revolving credit facility with a new $400 million revolving credit facility (the “Credit Facility”). The Credit Facility ends in June 2023, at which point any remaining outstanding borrowings would be due for repayment unless extended by agreement of the parties for up to two additional one-year periods. In addition, under the terms of the Credit Facility, Teradata from time to time and subject to certain conditions may increase the lending commitments under the Credit Facility in an aggregate principal amount up to an additional $200 million, to the extent that existing or new lenders agree to provide such additional commitments. The outstanding principal amount of the Credit Facility bears interest at a floating rate based upon, at Teradata’s option, a negotiated base rate or a Eurodollar rate plus, in each case, a margin based on Teradata’s leverage ratio. In the near term, Teradata would anticipate choosing a floating rate based on London Interbank Offered Rate (“LIBOR”). The Credit Facility is unsecured but is guaranteed by certain of Teradata’s material domestic subsidiaries and contains certain representations and warranties, conditions, affirmative, negative and financial covenants, and events of default customary for such facilities. As of September 30, 2019, the Company had no borrowings outstanding under the Credit Facility, leaving $400 million in additional borrowing capacity available under the Credit Facility. The Company was in compliance with all covenants under the Credit Facility as of September 30, 2019. Also, in June 2018, Teradata closed on a new senior unsecured $500 million five-year term loan, the proceeds of which plus additional cash-on-hand were used to pay off the remaining $525 million of principal on its previous term loan. The term loan is payable in quarterly installments, which commenced on June 30, 2019, with 1.25% of the initial principal amount due on each of the first eight payment dates; 2.50% of the initial principal amount due on each of the next four payment dates; 5.0% of the initial principal amount due on each of the next three payment dates; and all remaining principal due in June 2023. The outstanding principal amount of the term loan bears interest at a floating rate based upon a negotiated base rate or a Eurodollar rate, plus in each case, a margin based on the leverage ratio of the Company. As of September 30, 2019, the term loan principal outstanding was $488 million. As disclosed in Note 8, Teradata entered into an interest rate swap to hedge the floating interest rate of the term loan. As a result of the swap, Teradata’s fixed rate on the term loan equals 2.86% plus the applicable leverage-based margin as defined in the term loan agreement. As of September 30, 2019, the all-in fixed rate is 4.36%. The Company was in compliance with all covenants under the term loan as of September 30, 2019. Teradata’s term loan is recognized on the Company’s balance sheet at its unpaid principal balance and is not subject to fair value measurement. However, given that the loan carries a variable rate, the Company estimates that the unpaid principal balance of the term loan would approximate its fair value. If measured at fair value in the financial statements, the Company’s term loan would be classified as Level 2 in the fair value hierarchy.