Supplemental Guarantor Condensed Consolidating Financial Information, Balance Sheets (Unaudited) (Details) - USD ($) $ in Millions		May. 31, 2015	Aug. 31, 2014	May. 31, 2014	Aug. 31, 2013
Current Assets [Abstract]
Cash and cash equivalents		$ 4,449	$ 2,646	$ 2,126	$ 2,106
Accounts receivable, net		6,899	3,218
Inventories		8,764	6,076
Current intercompany loan receivable		0	0
Other current assets		917	302
Total Current Assets		21,029	12,242
Non-Current Assets [Abstract]
Property, plant and equipment, at cost, less accumulated depreciation and amortization		15,241	12,257
Equity investment in Alliance Boots		0	7,336
Goodwill		17,361	2,359
Intangible assets		11,229	1,180
Other non-current assets		5,784	1,876
Non-current intercompany loan receivable		0	0
Investment in subsidiaries		0	0
Total Non-Current Assets		49,615	25,008
Total Assets		70,644	37,250
Current Liabilities [Abstract]
Short-term borrowings		1,192	774
Trade accounts payable		9,932	4,315
Current intercompany loan payable		0	0
Accrued expenses and other liabilities		4,849	3,701
Income taxes		184	105
Total Current Liabilities		16,157	8,895
Non-Current Liabilities [Abstract]
Long-term debt	[1]	15,055	3,716
Deferred income taxes		3,532	1,080
Non-current intercompany loan payable		0	0
Other non-current liabilities		3,971	2,942
Total Non-Current Liabilities		22,558	7,738
Equity [Abstract]
Total Walgreens Boots Alliance, Inc. Shareholders' Equity		31,563	20,513
Noncontrolling interests		366	104
Total Equity		31,929	20,617
Total Liabilities and Equity		70,644	37,250
Guarantor Subsidiary [Member]
Current Assets [Abstract]
Cash and cash equivalents		2,703	2,224	$ 1,781	1,771
Accounts receivable, net		2,051	1,860
Inventories		4,053	4,301
Current intercompany loan receivable		13,695	6,755
Other current assets		856	176
Total Current Assets		23,358	15,316
Non-Current Assets [Abstract]
Property, plant and equipment, at cost, less accumulated depreciation and amortization		6,265	6,932
Equity investment in Alliance Boots		0	0
Goodwill		8,920	343
Intangible assets		332	417
Other non-current assets		339	232
Non-current intercompany loan receivable		0	0
Investment in subsidiaries		11,184	23,250
Total Non-Current Assets		27,040	31,174
Total Assets		50,398	46,490
Current Liabilities [Abstract]
Short-term borrowings		8	766
Trade accounts payable		4,078	3,850
Current intercompany loan payable		12,709	8,277
Accrued expenses and other liabilities		2,358	3,044
Income taxes		0	0
Total Current Liabilities		19,153	15,937
Non-Current Liabilities [Abstract]
Long-term debt		3,721	3,706
Deferred income taxes		293	404
Non-current intercompany loan payable		16,545	3,560
Other non-current liabilities		2,551	2,370
Total Non-Current Liabilities		23,110	10,040
Equity [Abstract]
Total Walgreens Boots Alliance, Inc. Shareholders' Equity		8,135	20,513
Noncontrolling interests		0	0
Total Equity		8,135	20,513
Total Liabilities and Equity		50,398	46,490
Non-guarantor Subsidiaries [Member]
Current Assets [Abstract]
Cash and cash equivalents		1,732	422	345	335
Accounts receivable, net		4,848	1,358
Inventories		4,711	1,775
Current intercompany loan receivable		26,531	8,277
Other current assets		641	141
Total Current Assets		38,463	11,973
Non-Current Assets [Abstract]
Property, plant and equipment, at cost, less accumulated depreciation and amortization		8,976	5,325
Equity investment in Alliance Boots		0	7,336
Goodwill		8,441	2,016
Intangible assets		10,897	763
Other non-current assets		5,445	1,644
Non-current intercompany loan receivable		4,286	3,560
Investment in subsidiaries		0	0
Total Non-Current Assets		38,045	20,644
Total Assets		76,508	32,617
Current Liabilities [Abstract]
Short-term borrowings		437	8
Trade accounts payable		5,854	465
Current intercompany loan payable		24,466	6,755
Accrued expenses and other liabilities		2,066	657
Income taxes		217	120
Total Current Liabilities		33,040	8,005
Non-Current Liabilities [Abstract]
Long-term debt		57	10
Deferred income taxes		3,239	676
Non-current intercompany loan payable		6,842	0
Other non-current liabilities		1,239	572
Total Non-Current Liabilities		11,377	1,258
Equity [Abstract]
Total Walgreens Boots Alliance, Inc. Shareholders' Equity		31,725	23,250
Noncontrolling interests		366	104
Total Equity		32,091	23,354
Total Liabilities and Equity		76,508	32,617
Parent Company [Member]
Current Assets [Abstract]
Cash and cash equivalents		14	0	0	0
Accounts receivable, net		0	0
Inventories		0	0
Current intercompany loan receivable		20,238	0
Other current assets		3	0
Total Current Assets		20,255	0
Non-Current Assets [Abstract]
Property, plant and equipment, at cost, less accumulated depreciation and amortization		0	0
Equity investment in Alliance Boots		0	0
Goodwill		0	0
Intangible assets		0	0
Other non-current assets		0	0
Non-current intercompany loan receivable		19,101	0
Investment in subsidiaries		28,676	0
Total Non-Current Assets		47,777	0
Total Assets		68,032	0
Current Liabilities [Abstract]
Short-term borrowings		747	0
Trade accounts payable		0	0
Current intercompany loan payable		23,289	0
Accrued expenses and other liabilities		425	0
Income taxes		550	0
Total Current Liabilities		25,011	0
Non-Current Liabilities [Abstract]
Long-term debt		11,277	0
Deferred income taxes		0	0
Non-current intercompany loan payable		0	0
Other non-current liabilities		181	0
Total Non-Current Liabilities		11,458	0
Equity [Abstract]
Total Walgreens Boots Alliance, Inc. Shareholders' Equity		31,563	0
Noncontrolling interests		0	0
Total Equity		31,563	0
Total Liabilities and Equity		68,032	0
Consolidating Adjustments [Member]
Current Assets [Abstract]
Cash and cash equivalents		0	0	$ 0	$ 0
Accounts receivable, net		0	0
Inventories		0	0
Current intercompany loan receivable		(60,464)	(15,032)
Other current assets		(583)	(15)
Total Current Assets		(61,047)	(15,047)
Non-Current Assets [Abstract]
Property, plant and equipment, at cost, less accumulated depreciation and amortization		0	0
Equity investment in Alliance Boots		0	0
Goodwill		0	0
Intangible assets		0	0
Other non-current assets		0	0
Non-current intercompany loan receivable		(23,387)	(3,560)
Investment in subsidiaries		(39,860)	(23,250)
Total Non-Current Assets		(63,247)	(26,810)
Total Assets		(124,294)	(41,857)
Current Liabilities [Abstract]
Short-term borrowings		0	0
Trade accounts payable		0	0
Current intercompany loan payable		(60,464)	(15,032)
Accrued expenses and other liabilities		0	0
Income taxes		(583)	(15)
Total Current Liabilities		(61,047)	(15,047)
Non-Current Liabilities [Abstract]
Long-term debt		0	0
Deferred income taxes		0	0
Non-current intercompany loan payable		(23,387)	(3,560)
Other non-current liabilities		0	0
Total Non-Current Liabilities		(23,387)	(3,560)
Equity [Abstract]
Total Walgreens Boots Alliance, Inc. Shareholders' Equity		(39,860)	(23,250)
Noncontrolling interests		0	0
Total Equity		(39,860)	(23,250)
Total Liabilities and Equity		$ (124,294)	$ (41,857)

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