Income Tax Expense by Fiscal Year (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016		Sep. 30, 2015
Current:
U.S. federal	$ 2,377	$ 2,250		$ 1,991
State and local	291	181		168
Non-U.S.	629	368		300
Total current taxes	3,297	2,799		2,459
Deferred:
U.S. federal	1,607	(508)		181
State and local	66	(63)		1
Non-U.S.	25	(207)		26
Total deferred taxes	1,698	(778)		208
Income tax provision	$ 4,995	$ 2,021	[1]	$ 2,667

[1] See Note 2—Visa Europe.