Short-Term Borrowings and Long-Term Debt (Details)				6 Months Ended				3 Months Ended					6 Months Ended			3 Months Ended			3 Months Ended		3 Months Ended								6 Months Ended
	Feb. 28, 2015 USD ($)	Dec. 31, 2014	Aug. 31, 2014 USD ($)	Feb. 28, 2015 Commercial Paper [Member] USD ($)	Feb. 28, 2014 Commercial Paper [Member] USD ($)	Feb. 28, 2015 Term Loan [Member] USD ($)	Feb. 28, 2015 Term Loan [Member] GBP (£)	Feb. 28, 2015 Revolving Credit Facility [Member] USD ($)	Feb. 28, 2015 Revolving Credit Facility [Member] Upon the affirmative vote [Member] USD ($)	Feb. 28, 2015 Letter of Credit [Member] USD ($)	Feb. 28, 2015 Letter of Credit [Member] Upon the affirmative vote [Member] USD ($)	Feb. 28, 2015 Term loan and revolving credit agreement [Member] USD ($)	Feb. 28, 2015 Alliance Boots [Member] USD ($)	Feb. 28, 2015 United Kingdom, Pounds	Feb. 28, 2015 Euro Member Countries, Euro	Feb. 28, 2015 Total $8.0 billion debt issuance [Member] USD ($)	Feb. 28, 2015 Total $4.0 billion debt issuance [Member] USD ($)	Aug. 31, 2014 Total $4.0 billion debt issuance [Member] USD ($)	Feb. 28, 2015 Total $1.0 billion debt issuance [Member] USD ($)	Aug. 31, 2014 Total $1.0 billion debt issuance [Member] USD ($)	Feb. 28, 2015 Euro and Pound Sterling Notes [Member] USD ($)	Feb. 28, 2015 Unsecured Variable Rate Notes Due 2016 [Member]	Feb. 28, 2015 1.750% unsecured notes due 2017 [Member]	Feb. 28, 2015 2.700% unsecured notes due 2019 [Member]	Feb. 28, 2015 3.300% unsecured notes due 2021 [Member]	Feb. 28, 2015 3.800% unsecured notes due 2024 [Member]	Feb. 28, 2015 4.500% unsecured notes due 2034 [Member]	Feb. 28, 2015 4.800% unsecured notes due 2044 [Member]	Feb. 28, 2015 Notes Due 2014 [Member] USD ($)	Feb. 28, 2015 1.000% Unsecured Notes Due 2015 [Member] USD ($)	Feb. 28, 2015 1.800% Unsecured Notes Due 2017 [Member]	Feb. 28, 2015 3.100% Unsecured Notes Due 2022 [Member]	Feb. 28, 2015 4.400% Unsecured Notes Due 2042 [Member]	Feb. 28, 2015 Variable Rate Borrowings [Member] USD ($)
Long-Term Debt [Abstract]
Other short-term borrowings	$ 1,061,000,000		$ 774,000,000																															$ 29,000,000
Spot rate		1.56												1.54	1.12
Repayment of debt													9,000,000,000																550,000,000	750,000,000
Debt instrument, description of variable rate basis																						Three-month U.S. Dollar LIBOR
Basis spread on variable rate (in hundredths)																						0.45%
Net proceeds from notes payable																7,900,000,000	4,000,000,000		1,000,000,000
Total issuance costs																44,000,000	26,000,000		8,000,000		11,000,000
Fair value of the notes																8,300,000,000	3,500,000,000	3,400,000,000	1,100,000,000	1,100,000,000	2,000,000,000
Maximum aggregate outstanding amount of indebtedness																2,000,000,000					2,000,000,000
Stated interest rate (in hundredths)																			5.25%
Interest payment frequency																			semiannually in arrears on January 15 and July 15
Percentage of principal amount of fixed rate notes can be redeemed (in hundredths)																100.00%	100.00%		100.00%
Redemption of notes description																Redemption price equal to the greater of : (1) 100% of the principal amount of the fixed rate notes being redeemed; and (2) the sum of the present values of the remaining scheduled payments of principal and interest thereon (not including any portion of such payments of interest accrued as of the redemption date), discounted to the redemption date on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) at the Treasury Rate (as defined in the applicable series of notes), plus 15 basis points for the notes due 2017, 15 basis points for the notes due 2019, 20 basis points for the notes due 2021, 20 basis points for the notes due 2024, 20 basis points for the notes due 2034 and 25 basis points for the notes due 2044.	Redemption price equal to the greater of: (a) 100% of the principal amount of the notes being redeemed; and (b) the sum of the present values of the remaining scheduled payments of principal and interest thereon (not including any portion of such payments of interest accrued as of the date of redemption), discounted to the date of redemption on a semiannual basis (assuming a 360-day year consisting of twelve 30-day months) at the Treasury Rate (as defined in the applicable series of notes), plus 12 basis points for the notes due 2015, 20 basis points for the notes due 2017, 22 basis points for the notes due 2022 and 25 basis points for the notes due 2042.		Redemption price equal to the greater of: (a) 100% of the principal amount of the notes to be redeemed; or (b) the sum of the present values of the remaining scheduled payments of principal and interest, discounted to the date of redemption on a semiannual basis at the Treasury Rate (as defined in the applicable series of notes), plus 45 basis points, plus accrued interest on the notes to be redeemed to, but excluding, the date of redemption.		Redemption price equal to rge greater of: (1) 100% of the principal amount of the notes to be redeemed; and (2) the sum of the present values of the remaining scheduled payments of principal and interest thereon (not including any portion of such payments of interest accrued as of the redemption date), discounted to the redemption date on an annual basis at the applicable Comparable Government Bond Rate, (as defined in the applicable series of notes), plus 20 basis points for the Euro notes, 20 basis points for the Pound Sterling notes due 2020 and 20 basis points for Pound Sterling the notes due 2025.		At any time in whole or from time to time in part	At any time prior to October 18, 2019 in whole or from time to time prior to October 18, 2019 in part	At any time prior to September 18, 2021 in whole or from time to time prior to September 18, 2021 in part	At any time prior to August 18, 2024 in whole or from time to time prior to August 18, 2024 in part	At any time prior to May 18, 2034 in whole or from time to time prior to May 18, 2034 in part	At any time prior to May 18, 2044 in whole or from time to time prior to May 18, 2044 in part
Basis points added to treasury rate to calculate redemption rate (in hundredths)																			45		20		15	15	20	20	20	25		12	20	22	25
Percentage of redemption price (in hundredths)																100.00%	100.00%				100.00%
Percentage of principal amount required on triggering event to repurchase notes (in hundredths)																101.00%	101.00%		101.00%		101.00%
Line of Credit Facility [Line Items]
Balance outstanding at fiscal year-end				0	0
Average daily short-term borrowings				4,000,000	14,000,000
Weighted-average interest rate (in hundredths)				0.02%	0.23%
Maximum borrowing capacity						2,200,000,000	1,450,000,000	2,250,000,000	3,000,000,000	375,000,000	500,000,000
Amount borrowed							1,450,000,000
Term of facility								5 years
Fees related to borrowings												$ 14,000,000