Accumulated other comprehensive loss (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Feb. 28, 2025	Feb. 29, 2024	Feb. 28, 2025	Feb. 29, 2024
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 11,165	$ 27,588	$ 12,005	$ 28,322
Total other comprehensive income (loss)	(8)	100	(88)	95
Ending balance	7,153	15,192	7,153	15,192
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(2,971)	(2,995)	(2,897)	(2,993)
Other comprehensive income (loss) before reclassification adjustments	(40)	108	(117)	117
Amounts reclassified from AOCI	41	17	46	20
Tax provision	(10)	(26)	(11)	(40)
Total other comprehensive income (loss)	(9)	99	(83)	96
Ending balance	(2,980)	(2,897)	(2,980)	(2,897)
Pension/ post-retirement obligations
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(702)	(642)	(706)	(698)
Other comprehensive income (loss) before reclassification adjustments	0	51	0	127
Amounts reclassified from AOCI	5	(4)	9	(7)
Tax provision	(1)	(12)	(2)	(31)
Total other comprehensive income (loss)	4	34	7	90
Ending balance	(698)	(608)	(698)	(608)
Unrealized gain (loss) on cash flow hedges and other
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance		(1)	(1)	(6)
Other comprehensive income (loss) before reclassification adjustments		0	1	0
Amounts reclassified from AOCI		1	0	5
Tax provision		0	0	0
Total other comprehensive income (loss)		0	1	5
Ending balance	0	0	0	0
Net investment hedges gain
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	107	86	15	83
Other comprehensive income (loss) before reclassification adjustments	2	(1)	94	7
Amounts reclassified from AOCI	0	0	0	(4)
Tax provision	0	0	0	(1)
Total other comprehensive income (loss)	2	(1)	94	2
Ending balance	109	85	109	85
Share of OCI of equity method investments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(58)	(147)	(88)	(132)
Other comprehensive income (loss) before reclassification adjustments	(42)	41	(13)	13
Amounts reclassified from AOCI	37	20	37	28
Tax provision	(9)	(14)	(9)	(9)
Total other comprehensive income (loss)	(15)	48	15	33
Ending balance	(73)	(100)	(73)	(100)
Cumulative translation adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(2,318)	(2,291)	(2,118)	(2,240)
Other comprehensive income (loss) before reclassification adjustments	1	17	(199)	(31)
Amounts reclassified from AOCI	0	0	0	(2)
Tax provision	0	0	0	0
Total other comprehensive income (loss)	1	17	(199)	(34)
Ending balance	$ (2,317)	$ (2,274)	$ (2,317)	$ (2,274)