v3.21.2
Revenues - Disaggregation of Revenue (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2019
Disaggregation of Revenue [Line Items]      
Net revenues $ 24,105 $ 21,846 $ 22,977
U.S.      
Disaggregation of Revenue [Line Items]      
Net revenues 11,160 10,125 10,279
International      
Disaggregation of Revenue [Line Items]      
Net revenues 12,945 11,721 12,698
Service revenues      
Disaggregation of Revenue [Line Items]      
Net revenues 11,475 9,804 9,700
Data processing revenues      
Disaggregation of Revenue [Line Items]      
Net revenues 12,792 10,975 10,333
International transaction revenues      
Disaggregation of Revenue [Line Items]      
Net revenues 6,530 6,299 7,804
Other revenues      
Disaggregation of Revenue [Line Items]      
Net revenues 1,675 1,432 1,313
Client incentives      
Disaggregation of Revenue [Line Items]      
Net revenues $ (8,367) $ (6,664) $ (6,173)