Document and Entity Information Document - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Nov. 10, 2017	Mar. 31, 2017
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, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 164,100
Class A common stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		1,813,463,251
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		12,665,935