Borrowings - Short and Long-Term Debt (Details) - USD ($) $ in Millions	6 Months Ended
Feb. 28, 2017	Aug. 31, 2016
Debt Instrument [Line Items]
Total short-term borrowings	$ 1,153	$ 323
Other	33	32
Total long-term debt, less current portion	$ 17,758	18,705
Unsecured Pound Sterling variable rate term loan due 2019
Debt Instrument [Line Items]
Maturity year	2019
Other
Debt Instrument [Line Items]
Total short-term borrowings	$ 315	260
Term Loan \| Unsecured Pound Sterling variable rate term loan due 2019
Debt Instrument [Line Items]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	1,711	1,833
Unsecured Notes \| 1.750% unsecured notes due 2017
Debt Instrument [Line Items]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	$ 0	746
Stated interest rate	1.75%
Maturity year	2017
Unsecured Notes \| 1.750% unsecured notes due 2018
Debt Instrument [Line Items]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	$ 1,247	1,246
Stated interest rate	1.75%
Maturity year	2018
Unsecured Notes \| 2.600% unsecured notes due 2021
Debt Instrument [Line Items]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	$ 1,494	1,493
Stated interest rate	2.60%
Maturity year	2021
Unsecured Notes \| 3.100% unsecured notes due 2023
Debt Instrument [Line Items]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	$ 745	744
Stated interest rate	3.10%
Maturity year	2023
Unsecured Notes \| 3.450% unsecured notes due 2026
Debt Instrument [Line Items]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	$ 1,886	1,885
Stated interest rate	3.45%
Maturity year	2026
Unsecured Notes \| 4.650% unsecured notes due 2046
Debt Instrument [Line Items]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	$ 590	590
Stated interest rate	4.65%
Maturity year	2046
Unsecured Notes \| 2.700% unsecured notes due 2019
Debt Instrument [Line Items]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	$ 1,245	1,244
Stated interest rate	2.70%
Maturity year	2019
Unsecured Notes \| 3.300% unsecured notes due 2021
Debt Instrument [Line Items]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	$ 1,243	1,242
Stated interest rate	3.30%
Maturity year	2021
Unsecured Notes \| 3.800% unsecured notes due 2024
Debt Instrument [Line Items]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	$ 1,987	1,987
Stated interest rate	3.80%
Maturity year	2024
Unsecured Notes \| 4.500% unsecured notes due 2034
Debt Instrument [Line Items]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	$ 494	494
Stated interest rate	4.50%
Maturity year	2034
Unsecured Notes \| 4.800% unsecured notes due 2044
Debt Instrument [Line Items]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	$ 1,492	1,492
Stated interest rate	4.80%
Maturity year	2044
Unsecured Notes \| 2.875% unsecured Pound Sterling notes due 2020
Debt Instrument [Line Items]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	$ 495	521
Stated interest rate	2.875%
Maturity year	2020
Unsecured Notes \| 3.600% unsecured Pound Sterling notes due 2025
Debt Instrument [Line Items]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	$ 371	391
Stated interest rate	3.60%
Maturity year	2025
Unsecured Notes \| 2.125% unsecured Euro notes due 2026
Debt Instrument [Line Items]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	$ 790	830
Stated interest rate	2.125%
Maturity year	2026
Unsecured Notes \| 3.100% unsecured notes due 2022
Debt Instrument [Line Items]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	$ 1,194	1,194
Stated interest rate	3.10%
Maturity year	2022
Unsecured Notes \| 4.400% unsecured notes due 2042
Debt Instrument [Line Items]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	$ 492	492
Stated interest rate	4.40%
Maturity year	2042
Unsecured Notes \| 5.250% unsecured notes due 2019
Debt Instrument [Line Items]
Carrying value of notes, net of unamortized discount and interest rate swap FMV adjustment	$ 249	249
Stated interest rate	5.25%
Maturity year	2019
Notes Payable \| 1.750% unsecured notes due 2017
Debt Instrument [Line Items]
Total short-term borrowings	$ 748	0
Stated interest rate	1.75%
Maturity year	2017
Term Loan \| Unsecured Pound Sterling variable rate term loan due 2019
Debt Instrument [Line Items]
Total short-term borrowings	$ 90	$ 63
Maturity year	2019

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Amount of long-term debt classified as other.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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