Document And Entity Information - shares	3 Months Ended
	Mar. 30, 2019	May 03, 2019
Document And Entity Information [Abstract]
Entity Registrant Name	REGAL BELOIT CORP
Entity Central Index Key	0000082811
Document Type	10-Q
Document Period End Date	Mar. 30, 2019
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-28
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		42,817,814