Related Parties Related Parties (Details) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
|
Sep. 30, 2015
USD ($)
entity
|
Sep. 30, 2014
USD ($)
entity
|
Sep. 30, 2013
USD ($)
|
|
| Related Party Disclosures [Abstract] | |||
| Minimum ownership of Visa stock to be considered a related party, percent | 10.00% | ||
| Minimum ownership interest in investee to be considered a related party, percent | 10.00% | ||
| Number of entities owning more than 10% of Visa's total voting stock | entity | 0 | 0 | |
| Significant transactions with related parties | $ 0 | $ 0 | $ 0 |