Significant Accounting Policies - Plant, equipment and depreciation (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Property, Plant and Equipment [Line Items]
Land and land improvements	$ 345,746	$ 281,040
Buildings and building equipment	1,773,041	1,567,130
Machinery and equipment	3,515,842	3,223,585
Construction in progress	176,052	114,975
Total	$ 5,810,681	$ 5,186,730
Buildings
Property, Plant and Equipment [Line Items]
Useful life	40 years
Land Improvements
Property, Plant and Equipment [Line Items]
Useful life	15 years
Machinery and Equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life	7 years
Machinery and Equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life	10 years
Vehicles and Office Equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life	3 years
Vehicles and Office Equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life	8 years