Segment reporting (Details) $ in Millions	3 Months Ended	6 Months Ended
Feb. 28, 2018 USD ($)	Feb. 28, 2017 USD ($)	Feb. 28, 2018 USD ($) segment	Feb. 28, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments \| segment			3
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	$ 33,021	$ 29,446	$ 63,761	$ 57,947
Adjusted operating income	2,163	2,016	3,972	3,742
Acquisition-related amortization	(113)	(82)	(198)	(164)
Acquisition-related costs	(65)	(29)	(116)	(46)
Certain legal and regulatory accruals and settlements	(90)		(115)
LIFO provision	(43)	(49)	(97)	(107)
Hurricane-related costs			(83)
Adjustments to equity earnings in AmerisourceBergen	113	(37)	(76)	(78)
Asset recovery	15		15
Cost transformation		(340)		(421)
Operating income	1,980	1,479	3,302	2,926
Retail Pharmacy USA
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	24,478	21,814	46,967	42,473
Adjusted operating income	1,649	1,552	3,026	2,841
Retail Pharmacy International
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	3,317	3,101	6,400	6,063
Adjusted operating income	280	242	490	455
Pharmaceutical Wholesale
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	5,226	4,531	10,394	9,411
Adjusted operating income	231	226	455	450
Reportable Segments
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	33,021	29,446	63,761	57,947
Reportable Segments \| Retail Pharmacy USA
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	24,478	21,814	46,967	42,473
Adjusted operating income	1,649	1,552	3,026	2,841
Reportable Segments \| Retail Pharmacy International
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	3,317	3,101	6,400	6,063
Adjusted operating income	280	242	490	455
Reportable Segments \| Pharmaceutical Wholesale
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	5,755	5,030	11,473	10,447
Adjusted operating income	231	226	455	450
Eliminations
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	(529)	(499)	(1,079)	(1,036)
Adjusted operating income	3	(4)	1	(4)
Eliminations \| Retail Pharmacy USA
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	0	0	0	0
Eliminations \| Retail Pharmacy International
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	0	0	0	0
Eliminations \| Pharmaceutical Wholesale
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	$ 529	$ 499	$ 1,079	$ 1,036

The amount of expense recognized in the current period that reflects the allocation of capitalized costs associated with acquisition of business. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274

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-Section 45
-Paragraph 28
-Subparagraph (b)
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This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

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Amount of gain (loss) recognized in settlement of litigation and insurance claims. Excludes claims within an insurance entity's normal claims settlement process.

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The change in the inventory reserve representing the cumulative difference in cost between the first in, first out and the last in, first out inventory valuation methods, which change has been reflected in the statement of income during the period.

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The charge against earnings in the period for the uninsured portion of a loss from a fire, explosion, or natural disaster (hurricane, earthquake).

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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The net result for the period of deducting operating expenses from operating revenues.

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Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The total amount of adjusted operating income, the components of which are not separately disclosed on the income statement, from items that are associated with the entity's normal revenue producing operation.

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This item represents the adjustments to equity earnings proportionate share for the period of the net income (loss) of AmerisourceBergen (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied.

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Asset Recovery

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The aggregate cost incurred for transformation of goods produced and sold and services rendered during the reporting period.

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