Cover Page - shares	9 Months Ended
	Oct. 31, 2020	Nov. 30, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Oct. 31, 2020
Document Transition Report	false
Entity File Number	001-38982
Entity Registrant Name	Medallia, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	77-0558353
Entity Address, Address Line One	575 Market Street
Entity Address, Address Line Two	Suite 1850
Entity Address, City or Town	San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94105
City Area Code	650
Local Phone Number	321-3000
Title of 12(b) Security	Common Stock, $0.001 par value per share
Trading Symbol	MDLA
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		150,448,557
Entity Central Index Key	0001540184
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--01-31