Visa Europe (Details) $ / shares in Units, $ in Millions				3 Months Ended	9 Months Ended
	Jun. 21, 2016 EUR (€) shares	Jun. 21, 2016 USD ($) $ / shares shares	Nov. 02, 2015 EUR (€)	Jun. 30, 2016 USD ($) $ / shares	Jun. 30, 2016 USD ($) $ / shares	Jun. 30, 2015 USD ($)	Jun. 21, 2016 EUR (€)	Sep. 30, 2015 USD ($)
Class of Stock [Line Items]
Up-front cash consideration					$ 9,082	$ 93
Consideration, preferred stock of the Company					5,717	$ 0
Additional cash consideration payable on the third anniversary of closing				$ 1,209	$ 1,209			$ 0
Class A equivalent preferred stock
Class of Stock [Line Items]
Preferred stock, par value | $ / shares				$ 0.0001	$ 0.0001
U.K.& I preferred stock
Class of Stock [Line Items]
Preferred stock, par value | $ / shares				0.0001	0.0001
Europe preferred stock
Class of Stock [Line Items]
Preferred stock, par value | $ / shares				$ 0.0001	$ 0.0001
Visa Europe
Class of Stock [Line Items]
Share capital of Visa Europe acquired (percent)							100.00%
Up-front cash consideration	€ 12,200,000,000	$ 13,882
Shares issued or issuable at closing (shares) | shares	79,000,000	79,000,000
Consideration, preferred stock of the Company	€ 5,300,000,000	$ 6,100
Additional cash consideration payable on the third anniversary of closing | €							€ 1,000,000,000
Compound annual interest rate on additional consideration paid on third anniversary of closing (percent)							4.00%
Initial conversion rate of U.K.&I and Europe preferred stock into Class A equivalent preferred stock	13.952	13.952
Litigation liabilities that may be offset (percent)	70.00%	70.00%
Acquisition related costs					$ 152
Visa Europe | U.K.& I preferred stock
Class of Stock [Line Items]
Shares issued or issuable at closing (shares) | shares	2,480,466	2,480,466
Visa Europe | Europe preferred stock
Class of Stock [Line Items]
Shares issued or issuable at closing (shares) | shares	3,156,823	3,156,823
Visa Europe | Class A common stock
Class of Stock [Line Items]
Closing stock price (in USD per share) | $ / shares		$ 77.33
Loss Sharing Agreement | Visa Europe
Class of Stock [Line Items]
Loss sharing agreement | €			€ 1,000,000,000
Conversion rate of U.K.&I. preferred stock			0
Operating Expense | Visa Europe
Class of Stock [Line Items]
Acquisition related costs				$ 152
Professional Fee | Visa Europe
Class of Stock [Line Items]
Acquisition related costs				60
General and Administrative Expense | Visa Europe
Class of Stock [Line Items]
Acquisition related costs				$ 92