Accumulated other comprehensive income (loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Feb. 28, 2023	Feb. 28, 2022	Feb. 28, 2023	Feb. 28, 2022
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 24,582	$ 30,579	$ 29,366	$ 23,822
Net change in other comprehensive (loss) income	164	(24)	153	(220)
Ending balance	29,439	30,867	29,439	30,867
Pension/ post- retirement obligations
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(162)	(364)	(157)	(359)
Other comprehensive (loss) income before reclassification adjustments	0	1	0	0
Amounts reclassified from AOCI	(7)	(5)	(13)	(11)
Other		(6)		(6)
Tax benefit (provision)	2	2	3	3
Net change in other comprehensive (loss) income	(5)	(8)	(10)	(13)
Ending balance	(167)	(372)	(167)	(372)
Unrealized loss on cash flow hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(5)	(9)	(3)	(10)
Other comprehensive (loss) income before reclassification adjustments	(1)	0	(3)	0
Amounts reclassified from AOCI	1	1	0	1
Other		0		0
Tax benefit (provision)	0	0	0	(1)
Net change in other comprehensive (loss) income	0	0	(2)	1
Ending balance	(5)	(9)	(5)	(9)
Net investment hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	183	9	213	(35)
Other comprehensive (loss) income before reclassification adjustments	(57)	(22)	(96)	31
Amounts reclassified from AOCI	0	0	0	0
Other		0		0
Tax benefit (provision)	14	2	23	(8)
Net change in other comprehensive (loss) income	(43)	(20)	(73)	24
Ending balance	140	(11)	140	(11)
Unrealized gain (loss) on available for sale securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	1		1	96
Other comprehensive (loss) income before reclassification adjustments	(1)		(1)	450
Amounts reclassified from AOCI	0		0	(577)
Other				0
Tax benefit (provision)	0		0	31
Net change in other comprehensive (loss) income	(1)		(1)	(96)
Ending balance	0	0	0	0
Share of OCI of equity method investments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(250)	(74)	(254)	(29)
Other comprehensive (loss) income before reclassification adjustments	78	(105)	(25)	(165)
Amounts reclassified from AOCI	40	0	150	0
Other		0		0
Tax benefit (provision)	(30)	26	(33)	40
Net change in other comprehensive (loss) income	88	(80)	92	(125)
Ending balance	(162)	(154)	(162)	(154)
Cumulative translation adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(2,583)	(1,863)	(2,605)	(1,772)
Other comprehensive (loss) income before reclassification adjustments	133	78	158	(9)
Amounts reclassified from AOCI	(11)	3	(14)	(1)
Other		0		0
Tax benefit (provision)	0	0	0	0
Net change in other comprehensive (loss) income	122	81	144	(10)
Ending balance	(2,461)	(1,782)	(2,461)	(1,782)
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(2,815)	(2,301)	(2,805)	(2,109)
Other comprehensive (loss) income before reclassification adjustments	153	(48)	33	307
Amounts reclassified from AOCI	22	(1)	123	(587)
Other		(6)		(6)
Tax benefit (provision)	(15)	29	(6)	66
Net change in other comprehensive (loss) income	161	(26)	151	(220)
Ending balance	$ (2,654)	$ (2,328)	$ (2,654)	$ (2,328)