Accumulated other comprehensive income (loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Aug. 31, 2023	Aug. 31, 2022	Aug. 31, 2021
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 29,366	$ 23,822	$ 21,136
Total other comprehensive (loss) income	(176)	(728)	1,669
Ending balance	28,322	29,366	23,822
Accumulated other comprehensive loss
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(2,805)	(2,109)	(3,771)
Other comprehensive income (loss) before reclassification adjustments	(500)	(97)	1,022
Amounts reclassified from AOCI	121	(565)	6
Other		(6)
Business disposal			792
Tax (provision) benefit	190	(27)	(157)
Total other comprehensive (loss) income	(189)	(696)	1,663
Ending balance	(2,993)	(2,805)	(2,109)
Pension/post-retirement obligations
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(157)	(359)	(748)
Other comprehensive income (loss) before reclassification adjustments	(705)	278	532
Amounts reclassified from AOCI	(26)	(22)	(8)
Other		(6)
Business disposal			(4)
Tax (provision) benefit	190	(48)	(132)
Total other comprehensive (loss) income	(541)	203	389
Ending balance	(698)	(157)	(359)
Unrealized gain (loss) on cash flow hedges
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(3)	(10)	(31)
Other comprehensive income (loss) before reclassification adjustments	(7)	6	10
Amounts reclassified from AOCI	4	3	17
Other		0
Business disposal			0
Tax (provision) benefit	0	(2)	(6)
Total other comprehensive (loss) income	(2)	7	21
Ending balance	(5)	(3)	(10)
Net investment hedges
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	213	(35)	(34)
Other comprehensive income (loss) before reclassification adjustments	(172)	327	(6)
Amounts reclassified from AOCI	0	0	0
Other		0
Business disposal			0
Tax (provision) benefit	42	(79)	6
Total other comprehensive (loss) income	(130)	248	(1)
Ending balance	83	213	(35)
Unrealized gain (loss) on available for sale debt securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	1	96	0
Other comprehensive income (loss) before reclassification adjustments	(2)	451	127
Amounts reclassified from AOCI	0	(577)	0
Other		0
Business disposal			0
Tax (provision) benefit	1	32	(31)
Total other comprehensive (loss) income	(2)	(95)	96
Ending balance	0	1	96
Share of OCI of equity method investments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(254)	(29)	(10)
Other comprehensive income (loss) before reclassification adjustments	6	(326)	(24)
Amounts reclassified from AOCI	158	31	0
Other		0
Business disposal			0
Tax (provision) benefit	(42)	70	6
Total other comprehensive (loss) income	122	(226)	(18)
Ending balance	(132)	(254)	(29)
Cumulative translation adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(2,605)	(1,772)	(2,948)
Other comprehensive income (loss) before reclassification adjustments	379	(833)	384
Amounts reclassified from AOCI	(14)	0	(3)
Other		0
Business disposal			795
Tax (provision) benefit	0	0	0
Total other comprehensive (loss) income	364	(833)	1,176
Ending balance	$ (2,240)	$ (2,605)	$ (1,772)