Accumulated other comprehensive income (loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Feb. 29, 2024	Feb. 28, 2023	Feb. 29, 2024	Feb. 28, 2023
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 27,588	$ 24,582	$ 28,322	$ 29,366
Net change in other comprehensive (loss) income	100	164	95	153
Ending balance	15,192	29,439	15,192	29,439
Pension/ post-retirement obligations
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(642)	(162)	(698)	(157)
Other comprehensive income (loss) before reclassification adjustments	51	0	127	0
Amounts reclassified from AOCI	(4)	(7)	(7)	(13)
Tax provision	(12)	2	(31)	3
Net change in other comprehensive (loss) income	34	(5)	90	(10)
Ending balance	(608)	(167)	(608)	(167)
Unrealized loss on cash flow hedges and other
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(1)	(4)	(6)	(2)
Other comprehensive income (loss) before reclassification adjustments	0	(2)	0	(4)
Amounts reclassified from AOCI	1	1	5	0
Tax provision	0	0	0	0
Net change in other comprehensive (loss) income	0	(1)	5	(3)
Ending balance	0	(5)	0	(5)
Net investment hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	86	183	83	213
Other comprehensive income (loss) before reclassification adjustments	(1)	(57)	7	(96)
Amounts reclassified from AOCI	0	0	(4)	0
Tax provision	0	14	(1)	23
Net change in other comprehensive (loss) income	(1)	(43)	2	(73)
Ending balance	85	140	85	140
Share of OCI of equity method investments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(147)	(250)	(132)	(254)
Other comprehensive income (loss) before reclassification adjustments	41	78	13	(25)
Amounts reclassified from AOCI	20	40	28	150
Tax provision	(14)	(30)	(9)	(33)
Net change in other comprehensive (loss) income	48	88	33	92
Ending balance	(100)	(162)	(100)	(162)
Cumulative translation adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(2,291)	(2,583)	(2,240)	(2,605)
Other comprehensive income (loss) before reclassification adjustments	17	133	(31)	158
Amounts reclassified from AOCI	0	(11)	(2)	(14)
Tax provision	0	0	0	0
Net change in other comprehensive (loss) income	17	122	(34)	144
Ending balance	(2,274)	(2,461)	(2,274)	(2,461)
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(2,995)	(2,815)	(2,993)	(2,805)
Other comprehensive income (loss) before reclassification adjustments	108	153	117	33
Amounts reclassified from AOCI	17	22	20	123
Tax provision	(26)	(15)	(40)	(6)
Net change in other comprehensive (loss) income	99	161	96	151
Ending balance	$ (2,897)	$ (2,654)	$ (2,897)	$ (2,654)