Settlement Guarantee Management - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
Dec. 31, 2017	Sep. 30, 2017
Settlement Guarantee Management [Abstract]
Estimated Maximum Settlement Exposure	$ 71,300	$ 67,700
Covered settlement exposure	4,500	2,800
Estimated probability-weighted value of the guarantee	$ 3	$ 3

The fair value, as of the date of each statement of financial position presented, of the settlement risk guarantee.

No definition available.

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