CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Operating Activities
Net income	$ 2,070	$ 1,941
Adjustments to reconcile net income to net cash provided by operating activities:
Client incentives	1,041	788
Fair value adjustment for the Visa Europe put option	0	(255)
Share-based compensation (Note 10)	45	39
Excess tax benefit for share-based compensation	0	(36)
Depreciation and amortization of property, equipment, technology and intangible assets	146	120
Deferred income taxes	77	45
Right to recover for covered losses recorded in equity	(94)	0
Litigation provision	15	0
Other	13	5
Change in operating assets and liabilities:
Settlement receivable	56	(35)
Accounts receivable	(89)	(75)
Client incentives	(1,129)	(850)
Other assets	66	23
Accounts payable	(102)
Settlement payable	79	(36)
Accrued and other liabilities	316	317
Accrued litigation (Note 12)	13	(12)
Net cash provided by operating activities	2,508	1,979
Investing Activities
Purchases of property, equipment, technology and intangible assets	(171)	(126)
Investment securities, available-for-sale:
Purchases	(1,032)	(6,803)
Proceeds from maturities and sales	788	739
Purchases of / contributions to other investments	(2)	(8)
Proceeds / distributions from other investments	0	4
Net cash used in investing activities	(417)	(6,194)
Financing Activities
Dividends paid (Note 8)	(399)	(340)
Proceeds from issuance of senior notes (Note 5)	0	15,971
Debt issuance costs (Note 5)	0	(77)
Proceeds from issuance of commercial paper (Note 5)	566	0
Payments from litigation escrow account—U.S. retrospective responsibility plan (Note 3 and Note 12)	0	11
Cash proceeds from issuance of common stock under employee equity plans	56	29
Restricted stock and performance-based shares settled in cash for taxes	(60)	(81)
Excess tax benefit for share-based compensation	0	36
Net cash (used in) provided by financing activities	(1,730)	13,534
Effect of exchange rate changes on cash and cash equivalents	(156)	0
Increase in cash and cash equivalents	205	9,319
Cash and cash equivalents at beginning of year	5,619	3,518
Cash and cash equivalents at end of period	5,824	12,837
Supplemental Disclosure
Income taxes paid, net of refunds	96	79
Interest payments on debt (Note 5)	244	0
Accruals related to purchases of property, equipment, technology and intangible assets	69	40
Class A common stock
Financing Activities
Repurchase of class A common stock (Note 8)	$ (1,893)	$ (2,015)