Cover Page - shares	3 Months Ended
	May 02, 2020	May 22, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	May 02, 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	Canon’s Court, 22 Victoria Street
Entity Address, City or Town	Hamilton
Entity Address, Postal Zip Code	HM 12
Entity Address, Country	BM
City Area Code	441
Local Phone Number	296-6395
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		665,300,000
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001058057
Current Fiscal Year End Date	--01-30