Cover - shares	9 Months Ended
	Dec. 28, 2019	Jan. 31, 2020
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Dec. 28, 2019
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2020
Current Fiscal Year End Date	--03-28
Entity File Number	333-124824
Entity Registrant Name	RBC Bearings INC
Entity Central Index Key	0001324948
Entity Tax Identification Number	95-4372080
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	One Tribology Center
Entity Address, City or Town	Oxford
Entity Address, State or Province	CT
Entity Address, Postal Zip Code	06478
City Area Code	(203)
Local Phone Number	267-7001
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	ROLL
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		25,039,691