Document and Entity Information - shares	6 Months Ended
	Jul. 31, 2020	Aug. 31, 2020
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jul. 31, 2020
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Entity Registrant Name	SEACHANGE INTERNATIONAL INC
Entity Central Index Key	0001019671
Current Fiscal Year End Date	--01-31
Entity Filer Category	Accelerated Filer
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		37,556,067
Entity File Number	001-38828
Entity Tax Identification Number	04-3197974
Entity Address, Address Line One	500 Totten Pond Road
Entity Address, City or Town	Waltham
Entity Address, State or Province	MA
Entity Incorporation, State or Country Code	DE
Entity Address, Postal Zip Code	02451
City Area Code	(978)
Local Phone Number	897-0100
Document Quarterly Report	true
Document Transition Report	false
Common Stock [Member]
Document Information [Line Items]
Trading Symbol	SEAC
Title of 12(b) Security	Common Stock, $0.01 Par Value
Security Exchange Name	NASDAQ
Series A Preferred Stock [Member]
Document Information [Line Items]
Trading Symbol	SEAC
Title of 12(b) Security	Series A Participating Preferred Stock Purchase Rights
Security Exchange Name	NASDAQ