Technical Packaging Divestiture (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Jun. 30, 2020 USD ($)	Dec. 31, 2019 item	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)
Technical Packaging Divestiture
After-tax gain on the sale of business			$ 77,116
working capital adjustment	$ 200
Assets:
Current assets				$ 25,314
Liabilities:
Current liabilities				11,517
Other liabilities				3,999
Technical Packaging Business | Disposed of by Sale
Technical Packaging Divestiture
Net sales			16,500	86,900	$ 87,900
Pretax (loss) earnings			(300)	4,300	$ 6,900
Proceeds from sale of discontinued operations			184,000
After-tax gain on the sale of business			$ 76,500
Assets:
Accounts receivable, net				15,700
Contract assets, net				5,100
Inventories				3,900
Other current assets				600
Current assets				25,300
Property, plant & equipment, net				33,600
Intangible assets, net				11,400
Goodwill				19,000
Other assets				3,400
Total assets				92,700
Liabilities:
Accounts payable				7,600
Accrued expenses and other current liabilities				3,900
Current liabilities				11,500
Other liabilities				4,000
Total liabilities				$ 15,500
Technical Packaging Business | Sonoco Products Company | Disposed of by Sale
Technical Packaging Divestiture
Number of wholly-owned subsidiaries of the buyers | item		2