Document and Entity Information - shares	6 Months Ended
	Oct. 31, 2018	Nov. 30, 2018
Document Information [Line Items]
Entity Registrant Name	BROWN FORMAN CORP
Entity Central Index Key	0000014693
Document Type	10-Q
Document Period End Date	Oct. 31, 2018
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--04-30
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Common stock, Class A, voting [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		169,010,917
Common stock, Class B, nonvoting [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		307,948,847