Postretirement and Other Employee Benefits (Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Aug. 31, 2021	Aug. 31, 2020	Aug. 31, 2019
Retirement Benefits [Abstract]
Service cost	$ 25	$ 25	$ 1
Interest cost	5	3	3
Expected long-term return on plan assets	(16)	(15)	(5)
Recognized actuarial (gain) loss	(10)	(3)	1
Amortization of actuarial gains	(6)	0	0
Net settlement loss	1	0	1
Amortization of prior service costs	1	0	0
Net periodic benefit cost	$ 0	$ 10	$ 1
Gain (loss) corridor	10.00%	10.00%	10.00%