Settlement Guarantee Management - Additional Information (Detail) (USD $)	Mar. 31, 2012	Sep. 30, 2011
Settlement Guarantee Management [Abstract]
Estimated maximum settlement exposure	$ 49,900,000,000	$ 47,500,000,000
Covered settlement exposure	3,400,000,000	3,200,000,000
Estimated probability-weighted value of the guarantee	$ 1,000,000	$ 1,000,000

The amount represents settlement at risk (or exposure) and is estimated using the average daily volumes during the quarter multiplied by the estimated number of days to settle, and the total balance for outstanding travelers cheques.

No definition available.

Name:	v_EstimatedMaximumSettlementExposure
Namespace Prefix:	v_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant