Document and Entity Information Document - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2018	Nov. 09, 2018	Mar. 29, 2018
Entity Information [Line Items]
Entity Registrant Name	VISA INC.
Entity Central Index Key	0001403161
Current Fiscal Year End Date	--09-30
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 214,100
Class A common stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		1,759,797,999
Class B common stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		245,513,385
Class C common stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		11,706,272