Changes in the Escrow Account (Detail) - USD ($) $ in Millions |
3 Months Ended | 12 Months Ended | |||
|---|---|---|---|---|---|
Sep. 30, 2014 |
Sep. 30, 2015 |
Sep. 30, 2014 |
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| Escrow Account [Roll Forward] | |||||
| Litigation Escrow Account Balance, Beginning of Period | $ 1,498 | $ 49 | |||
| Return of takedown payments from settlement fund into the litigation escrow account | 0 | 1,056 | |||
| Litigation Escrow Account Balance, End of Period | $ 1,498 | 1,072 | 1,498 | ||
| Opt-out Merchants | |||||
| Escrow Account [Roll Forward] | |||||
| Payments to Settlement Funds | [1] | $ (426) | (57) | ||
| MasterCard [Member] | |||||
| Escrow Account [Roll Forward] | |||||
| Omnibus Loss Sharing Agreement Percentage | 33.3333% | ||||
| Visa | |||||
| Escrow Account [Roll Forward] | |||||
| Omnibus Loss Sharing Agreement Percentage | 66.6667% | ||||
| Covered Litigation | |||||
| Escrow Account [Roll Forward] | |||||
| Deposits into litigation escrow account | $ 450 | $ 0 | $ 450 | ||
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