v3.20.2
Cover Page - shares
shares in Millions
 9 Months Ended
Oct. 31, 2020
Nov. 27, 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 000-30877  
Entity Registrant Name MARVELL TECHNOLOGY GROUP LTD  
Entity Incorporation, State or Country Code D0  
Entity Tax Identification Number 77-0481679  
Entity Address, Address Line One Victoria Place, 5th Floor, 31 Victoria Street  
Entity Address, City or Town Hamilton  
Entity Address, Postal Zip Code HM 10  
Entity Address, Country BM  
City Area Code 441  
Local Phone Number 294-8096  
Title of 12(b) Security Common Stock, par value $0.002 per share  
Trading Symbol MRVL  
Security Exchange Name NASDAQ  
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  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   671.8
Amendment Flag false  
Document Fiscal Year Focus 2021  
Document Fiscal Period Focus Q3  
Entity Central Index Key 0001058057  
Current Fiscal Year End Date --01-30