Postretirement and Other Employee Benefits (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Feb. 28, 2022	Feb. 28, 2021	Feb. 28, 2022	Feb. 28, 2021	Aug. 31, 2021
Retirement Benefits [Abstract]
Service cost	$ 6	$ 8	$ 12	$ 13
Interest cost	1	1	2	2
Expected long-term return on plan assets	(4)	(5)	(8)	(8)
Recognized actuarial gain	(3)	(2)	(6)	(3)
Amortization of actuarial gains	(2)	(1)	(4)	(3)
Amortization of prior service credit	1	0	2	0
Net periodic benefit cost	$ (1)	$ 1	$ (2)	$ 1
Gain (loss) corridor	10.00%		10.00%		10.00%