Segment reporting - Restructuring Asset Impairment and Acquisition Related Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Restructuring, asset impairment and acquisition-related costs	$ 144,626	$ 113,289	$ 147,785
Operating segments | Consumer Packaging
Segment Reporting Information [Line Items]
Restructuring, asset impairment and acquisition-related costs	41,155	18,391	9,990
Operating segments | Display and Packaging
Segment Reporting Information [Line Items]
Restructuring, asset impairment and acquisition-related costs	(7,358)	19,046	2,082
Operating segments | Paper and Industrial Converted Products
Segment Reporting Information [Line Items]
Restructuring, asset impairment and acquisition-related costs	5,270	11,773	24,281
Operating segments | Protective Solutions
Segment Reporting Information [Line Items]
Restructuring, asset impairment and acquisition-related costs	9,083	1,529	3,071
Corporate
Segment Reporting Information [Line Items]
Restructuring, asset impairment and acquisition-related costs	$ 96,476	$ 62,550	$ 108,361