Significant Accounting Policies - Depreciation (Details) - USD ($) $ in Millions	12 Months Ended
	Aug. 31, 2019	Aug. 31, 2018	Aug. 31, 2017
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 57.5	$ 51.8	$ 46.6
Minimum | Building and related improvements
Property, Plant and Equipment [Line Items]
Useful lives of plant and equipment, minimum	10 years
Minimum | Machinery and equipment
Property, Plant and Equipment [Line Items]
Useful lives of plant and equipment, minimum	3 years
Maximum | Building and related improvements
Property, Plant and Equipment [Line Items]
Useful lives of plant and equipment, minimum	40 years
Maximum | Machinery and equipment
Property, Plant and Equipment [Line Items]
Useful lives of plant and equipment, minimum	15 years