Short-Term Borrowings and Long-Term Debt, Debt Issuance (Details) € in Millions, £ in Millions, $ in Millions	9 Months Ended
	May 31, 2016 USD ($)		May 31, 2016 GBP (£)		May 31, 2016 EUR (€)
Unsecured Variable Rate Notes Due 2016 [Member]
Debt Instrument [Line Items]
Maturity date	May 18, 2016
1.750% Unsecured Notes Due 2017 [Member]
Debt Instrument [Line Items]
Interest rate	1.75%	[1]	1.75%	[1]	1.75%	[1]
2.875% Unsecured Pound Sterling Notes Due 2020 [Member]
Debt Instrument [Line Items]
Maturity date	Nov. 20, 2020
3.300% Unsecured Notes Due 2021 [Member]
Debt Instrument [Line Items]
Interest rate	3.30%	[1]	3.30%	[1]	3.30%	[1]
3.100% Unsecured Notes Due 2022 [Member]
Debt Instrument [Line Items]
Interest rate	3.10%	[1]	3.10%	[1]	3.10%	[1]
3.800% Unsecured Notes Due 2024 [Member]
Debt Instrument [Line Items]
Interest rate	3.80%	[1]	3.80%	[1]	3.80%	[1]
2.125% Unsecured Euro Notes Due 2026 [Member]
Debt Instrument [Line Items]
Maturity date	Nov. 20, 2026
4.500% Unsecured Notes Due 2034 [Member]
Debt Instrument [Line Items]
Interest rate	4.50%	[1]	4.50%	[1]	4.50%	[1]
4.400% Unsecured Notes Due 2042 [Member]
Debt Instrument [Line Items]
Interest rate	4.40%	[1]	4.40%	[1]	4.40%	[1]
4.800% Unsecured Notes Due 2044 [Member]
Debt Instrument [Line Items]
Interest rate	4.80%	[1]	4.80%	[1]	4.80%	[1]
Unsecured Debt [Member] | 1.750% Unsecured Notes Due 2017 [Member]
Debt Instrument [Line Items]
Face amount of notes issued	$ 750
Maturity date	Nov. 17, 2017
Interest payment dates	May 17 and November 17; commencing on May 17, 2015
Interest rate	1.75%		1.75%		1.75%
Unsecured Debt [Member] | 2.700% Unsecured Notes Due 2019 [Member]
Debt Instrument [Line Items]
Face amount of notes issued	$ 1,250
Maturity date	Nov. 18, 2019
Interest payment dates	May 18 and November 18; commencing on May 18, 2015
Interest rate	2.70%		2.70%		2.70%
Unsecured Debt [Member] | 2.875% Unsecured Pound Sterling Notes Due 2020 [Member]
Debt Instrument [Line Items]
Face amount of notes issued | £			£ 400
Interest rate	2.875%		2.875%		2.875%
Unsecured Debt [Member] | 3.300% Unsecured Notes Due 2021 [Member]
Debt Instrument [Line Items]
Face amount of notes issued	$ 1,250
Maturity date	Nov. 18, 2021
Interest payment dates	May 18 and November 18; commencing on May 18, 2015
Interest rate	3.30%		3.30%		3.30%
Unsecured Debt [Member] | 3.100% Unsecured Notes Due 2022 [Member]
Debt Instrument [Line Items]
Face amount of notes issued	$ 1,200
Maturity date	Sep. 15, 2022
Interest payment dates	March 15 and September 15; commencing on March 15, 2013
Interest rate	3.10%		3.10%		3.10%
Unsecured Debt [Member] | 3.800% Unsecured Notes Due 2024 [Member]
Debt Instrument [Line Items]
Face amount of notes issued	$ 2,000
Maturity date	Nov. 18, 2024
Interest payment dates	May 18 and November 18; commencing on May 18, 2015
Interest rate	3.80%		3.80%		3.80%
Unsecured Debt [Member] | 3.600% Unsecured Pound Sterling Notes Due 2025 [Member]
Debt Instrument [Line Items]
Face amount of notes issued | £			£ 300
Maturity date	Nov. 20, 2025
Interest rate	3.60%		3.60%		3.60%
Unsecured Debt [Member] | 2.125% Unsecured Euro Notes Due 2026 [Member]
Debt Instrument [Line Items]
Face amount of notes issued | €					€ 750
Interest rate	2.125%		2.125%		2.125%
Unsecured Debt [Member] | 4.500% Unsecured Notes Due 2034 [Member]
Debt Instrument [Line Items]
Face amount of notes issued	$ 500
Maturity date	Nov. 18, 2034
Interest payment dates	May 18 and November 18; commencing on May 18, 2015
Interest rate	4.50%		4.50%		4.50%
Unsecured Debt [Member] | 4.400% Unsecured Notes Due 2042 [Member]
Debt Instrument [Line Items]
Face amount of notes issued	$ 500
Maturity date	Sep. 15, 2042
Interest payment dates	March 15 and September 15; commencing on March 15, 2013
Interest rate	4.40%		4.40%		4.40%
Unsecured Debt [Member] | 4.800% Unsecured Notes Due 2044 [Member]
Debt Instrument [Line Items]
Face amount of notes issued	$ 1,500
Maturity date	Nov. 18, 2044
Interest payment dates	May 18 and November 18; commencing on May 18, 2015
Interest rate	4.80%		4.80%		4.80%
Unsecured Debt [Member] | Pound Sterling Notes [Member]
Debt Instrument [Line Items]
Face amount of notes issued | £			£ 700
Unsecured Debt [Member] | Total $4.0 Billion Debt Issuance [Member]
Debt Instrument [Line Items]
Face amount of notes issued	$ 1,700
Unsecured Debt [Member] | Total $8.0 Billion Debt Issuance [Member]
Debt Instrument [Line Items]
Face amount of notes issued	$ 7,250

[1] All notes are presented net of unamortized discount and debt issuance costs, where applicable.