v3.3.0.814
Assumptions Used to Estimate the Fair Value of Each Stock Option on the Date of Grant Using a Black-Scholes Option Pricing Model (Detail) - $ / shares
 12 Months Ended
Sep. 30, 2015
Sep. 30, 2014
Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected term (in years)(1) [1] 4 years 6 months 18 days 4 years 9 months 18 days 6 years 29 days
Risk-free rate of return(2) [2] 1.50% 1.30% 0.80%
Expected volatility(3) [3] 22.00% 25.20% 29.30%
Expected dividend yield(4) [4] 0.80% 0.80% 0.90%
Fair value per option granted $ 12.04 $ 11.03 $ 9.76
Minimum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected volatility(3) 21.00%    
Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected volatility(3) 23.00%    
Visa      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected term peer weighted percentage 67.00% 58.00%  
Peer Companies [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected term peer weighted percentage 33.00% 42.00%  
[1] Beginning in fiscal 2014, assumption is based on the Company's historical option exercises and those of a set of peer companies that management believes is generally comparable to Visa. The Company's data is weighted based on the number of years between the measurement date and Visa's initial public offering as a percentage of the options' contractual term. The relative weighting placed on Visa's data and peer data in fiscal 2015 was approximately 67% and 33%, respectively, and the relative weighting in fiscal 2014 was 58% and 42%, respectively. In fiscal 2013, assumption was fully based on peer companies' data.
[2] Based upon the zero coupon U.S. treasury bond rate over the expected term of the awards.
[3] Based on the Company’s implied and historical volatility. The expected volatilities ranged from 21% to 23% in fiscal 2015. In fiscal 2013, historical volatility was a blend of Visa's historical volatility and those of comparable peer companies. The relative weighting between Visa historical volatility and the historical volatility of the peer companies was based on the percentage of years Visa stock price information is available since its initial public offering compared to the expected term.
[4] Based on the Company’s annual dividend rate on the date of grant.