Supplemental Guarantor Condensed Consolidating Financial Information, Statements of Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Feb. 28, 2015	Feb. 28, 2014	Feb. 28, 2015	Feb. 28, 2014
Statement of Comprehensive Income [Abstract]
Net Earnings (loss)	$ 2,060us-gaap_ProfitLoss	$ 730us-gaap_ProfitLoss	$ 2,937us-gaap_ProfitLoss	$ 1,462us-gaap_ProfitLoss
Other comprehensive income (loss), net of tax:
Postretirement liability	(8)	(2)	(9)	6
Unrealized gain (loss) on cash flow hedges	0	0	(12)	0
Changes in unrecognized gain (loss) on available-for-sale investments	90	(49)	189	35
Share of other comprehensive income (loss) of Alliance Boots	92	(19)	113	(56)
Currency translation adjustments	(301)	116	(490)	281
Other Comprehensive Income (loss) of subsidiaries	0	0	0	0
Total Other Comprehensive Income (loss)	(127)	46	(209)	266
Total Comprehensive Income (loss)	1,933us-gaap_ComprehensiveIncomeNetOfTax	776us-gaap_ComprehensiveIncomeNetOfTax	2,728us-gaap_ComprehensiveIncomeNetOfTax	1,728us-gaap_ComprehensiveIncomeNetOfTax
Comprehensive income attributable to noncontrolling interests	13	14	40	23
Comprehensive income attributable to Walgreens Boots Alliance, Inc.	1,920	762	2,688	1,705
Guarantor/Issuer Subsidiary [Member]
Statement of Comprehensive Income [Abstract]
Net Earnings (loss)	2,052	730	2,938	1,462
Other comprehensive income (loss), net of tax:
Postretirement liability	(1)	(2)	(2)	6
Unrealized gain (loss) on cash flow hedges	0	0	27	0
Changes in unrecognized gain (loss) on available-for-sale investments	0	0	0	0
Share of other comprehensive income (loss) of Alliance Boots	0	0	0	0
Currency translation adjustments	0	0	0	0
Other Comprehensive Income (loss) of subsidiaries	(127)	48	(196)	260
Total Other Comprehensive Income (loss)	(128)	46	(171)	266
Total Comprehensive Income (loss)	1,924	776	2,767	1,728
Comprehensive income attributable to noncontrolling interests	0	0	0	0
Comprehensive income attributable to Walgreens Boots Alliance, Inc.	1,924	776	2,767	1,728
Non-guarantor Subsidiaries [Member]
Statement of Comprehensive Income [Abstract]
Net Earnings (loss)	2,222	602	3,133	1,195
Other comprehensive income (loss), net of tax:
Postretirement liability	(7)	0	(7)	0
Unrealized gain (loss) on cash flow hedges	(1)	0	(1)	0
Changes in unrecognized gain (loss) on available-for-sale investments	90	(49)	189	35
Share of other comprehensive income (loss) of Alliance Boots	92	(19)	113	(56)
Currency translation adjustments	(301)	116	(490)	281
Other Comprehensive Income (loss) of subsidiaries	0	0	0	0
Total Other Comprehensive Income (loss)	(127)	48	(196)	260
Total Comprehensive Income (loss)	2,095	650	2,937	1,455
Comprehensive income attributable to noncontrolling interests	13	14	40	23
Comprehensive income attributable to Walgreens Boots Alliance, Inc.	2,082	636	2,897	1,432
Parent Company [Member]
Statement of Comprehensive Income [Abstract]
Net Earnings (loss)	2,060	0	2,937	0
Other comprehensive income (loss), net of tax:
Postretirement liability	0	0	0	0
Unrealized gain (loss) on cash flow hedges	1	0	(38)	0
Changes in unrecognized gain (loss) on available-for-sale investments	0	0	0	0
Share of other comprehensive income (loss) of Alliance Boots	0	0	0	0
Currency translation adjustments	0	0	0	0
Other Comprehensive Income (loss) of subsidiaries	(128)	0	(171)	0
Total Other Comprehensive Income (loss)	(127)	0	(209)	0
Total Comprehensive Income (loss)	1,933	0	2,728	0
Comprehensive income attributable to noncontrolling interests	0	0	0	0
Comprehensive income attributable to Walgreens Boots Alliance, Inc.	1,933	0	2,728	0
Consolidating Adjustments [Member]
Statement of Comprehensive Income [Abstract]
Net Earnings (loss)	(4,274)	(602)	(6,071)	(1,195)
Other comprehensive income (loss), net of tax:
Postretirement liability	0	0	0	0
Unrealized gain (loss) on cash flow hedges	0	0	0	0
Changes in unrecognized gain (loss) on available-for-sale investments	0	0	0	0
Share of other comprehensive income (loss) of Alliance Boots	0	0	0	0
Currency translation adjustments	0	0	0	0
Other Comprehensive Income (loss) of subsidiaries	255	(48)	367	(260)
Total Other Comprehensive Income (loss)	255	(48)	367	(260)
Total Comprehensive Income (loss)	(4,019)	(650)	(5,704)	(1,455)
Comprehensive income attributable to noncontrolling interests	0	0	0	0
Comprehensive income attributable to Walgreens Boots Alliance, Inc.	$ (4,019)	$ (650)	$ (5,704)	$ (1,455)

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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