Leases - annual minimum rental commitments (Details) $ in Millions	Aug. 31, 2018 USD ($)
Finance Lease Obligation [Abstract]
2019	$ 18
2020	18
2021	18
2022	18
2023	18
Later	216
Total minimum lease payments	306
Capital Lease [Abstract]
2019	63
2020	63
2021	62
2022	58
2023	57
Later	864
Total minimum lease payments	1,167
Operating Lease [Abstract]
2019	3,528
2020	3,304
2021	3,028
2022	2,762
2023	2,522
Later	17,592
Total minimum lease payments	$ 32,736

Amount of minimum lease payments for capital leases.

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