Segment reporting (Details) $ in Millions	3 Months Ended	9 Months Ended
May 31, 2017 USD ($)	May 31, 2016 USD ($)	May 31, 2017 USD ($) segment	May 31, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments \| segment			3
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	$ 30,118	$ 29,498	$ 88,065	$ 88,715
Adjusted operating income	1,914	1,814	5,656	5,653
Cost transformation	(171)	(73)	(592)	(191)
Acquisition-related amortization	(83)	(96)	(247)	(278)
LIFO provision	(97)	(92)	(204)	(206)
Adjustments to equity earnings in AmerisourceBergen	(17)	(5)	(95)	(5)
Acquisition-related costs	(29)	(15)	(75)	(82)
Asset impairment				(30)
Operating income	1,517	1,533	4,443	4,861
Retail Pharmacy USA
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	22,528	21,185	65,001	63,055
Adjusted operating income	1,463	1,382	4,304	4,257
Retail Pharmacy International
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	2,809	3,132	8,872	10,219
Adjusted operating income	193	258	648	908
Pharmaceutical Wholesale
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	4,781	5,181	14,192	15,441
Adjusted operating income	253	179	703	500
Reportable Segments
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	30,118	29,498	88,065	88,715
Reportable Segments \| Retail Pharmacy USA
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	22,528	21,185	65,001	63,055
Adjusted operating income	1,463	1,382	4,304	4,257
Reportable Segments \| Retail Pharmacy International
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	2,809	3,132	8,872	10,219
Adjusted operating income	193	258	648	908
Reportable Segments \| Pharmaceutical Wholesale
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	5,296	5,748	15,743	17,171
Adjusted operating income	253	179	703	500
Eliminations
Segment Reporting Information, Operating Income (Loss) [Abstract]
Sales	(515)	(567)	(1,551)	(1,730)
Adjusted operating income	5	(5)	1	(12)
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	$ 515	$ 567	$ 1,551	$ 1,730

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.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 45
-Paragraph 2
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-Paragraph 28
-Subparagraph (b)
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Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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

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