Other Assets - Schedule of Other Assets (Details) - USD ($) $ in Thousands	Aug. 31, 2017	Aug. 31, 2016	Aug. 31, 2015	Aug. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 154,055	$ 160,414	$ 150,115
Customer lists, trademarks and other intangible assets	33,330	44,766
Notes receivable	51,596	358,096
Deferred purchase price receivable	345,655	0
Long-term derivative assets	196,913	0
Prepaid pension and other benefits	122,433	120,693
Capitalized major maintenance	105,006	169,054	$ 241,588	$ 67,643
Cash Surrender Value of Life Insurance	118,677	112,193
Other	124,137	127,440
Other assets	1,251,802	1,092,656
Customer lists
Finite-Lived Intangible Assets [Line Items]
Customer lists, trademarks and other intangible assets	$ 33,330	$ 44,766