Other Assets - Schedule of Other Assets (Details) - USD ($) $ in Thousands	Aug. 31, 2019	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 172,404	$ 138,464	$ 138,454
Customer lists, trademarks and other intangible assets	71,206	29,338
Notes receivable	189,045	211,986
Long-term derivative assets	36,408	23,084
Prepaid pension and other benefits	73,100	101,539
Capitalized major maintenance	286,890	130,780	$ 105,006	$ 169,054
Cash value life insurance	122,792	123,010
Other	60,350	76,128
Other assets	1,012,195	834,329
Customer lists, trademarks and other intangible assets
Finite-Lived Intangible Assets [Line Items]
Customer lists, trademarks and other intangible assets	$ 71,206	$ 29,338