v3.3.0.814
Information that Causes the Income Tax Expense to Differ from the Amount of Income Tax Determined by Applying the Applicable U.S. Federal Statutory Rate of 35% to Pretax Income (Detail) - USD ($)
$ in Millions
12 Months Ended
Sep. 30, 2015
Sep. 30, 2014
Sep. 30, 2013
Income Tax Disclosure [Abstract]      
U.S. federal income tax at statutory rate $ 3,148 $ 2,704 $ 2,540
State income taxes, net of federal benefit 194 129 42
Non-U.S. tax effect, net of federal benefit (327) (278) (328)
Prior years U.S. domestic production activities deduction 0 (191) 0
Reversal of prior years tax reserves related to the resolution of uncertain tax positions (239) 0 0
Other, net (109) (78) 23
Income tax provision $ 2,667 $ 2,286 $ 2,277
U.S. federal income tax at statutory rate, percent 35.00% 35.00% 35.00%
State income taxes, net of federal benefit, percent 2.00% 2.00% 1.00%
Non-U.S. tax effect, net of federal benefit, percent (4.00%) (4.00%) (5.00%)
Prior years U.S. domestic production activities deduction, percent 0.00% (2.00%) 0.00%
Reversal of prior years tax reserves related to the resolution of uncertain tax positions, percent (2.00%) 0.00% 0.00%
Other, net, percent (1.00%) (1.00%) 0.00%
Income tax expense, percent 30.00% 30.00% 31.00%