Cover Page - shares	9 Months Ended
	Sep. 26, 2020	Oct. 26, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 26, 2020
Document Transition Report	false
Entity File Number	001-07283
Entity Registrant Name	REGAL BELOIT CORP
Entity Incorporation, State or Country Code	WI
Entity Tax Identification Number	39-0875718
Entity Address, Address Line One	200 State Street
Entity Address, City or Town	Beloit
Entity Address, State or Province	WI
Entity Address, Postal Zip Code	53511
City Area Code	608
Local Phone Number	364-8800
Title of 12(b) Security	Common Stock
Trading Symbol	RBC
Security Exchange Name	NYSE
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		40,595,282
Entity Central Index Key	0000082811
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--01-02