Business Acquisition, Number Of Mills Acquired

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Business Combination, Folding Carton Facilities Acquired, Number

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Business Combination, Number Of Facilities Acquired

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Goodwill Impairment, Restructuring and Other Charges [Abstract]

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Goodwill Impairment, Restructuring and Other Special Charges

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Number Of Converting Facilities

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Number Of Mills

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Other Special Charges

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Restructuring and Related Activities, Number of Mills Expected To Close

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Restructuring And Related Costs, Term Of Program

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This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

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Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee.

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Amount of gain (loss) from the difference between the sale price or salvage price and the book value of an asset that was sold or retired, and gain (loss) from the write down of assets from their carrying value to fair value.

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Amount of acquisition of long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

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Amount expected to be recognized in earnings for the specified restructuring cost.

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Discloses the amount charged against the accrued restructuring reserves, or earnings if not previously accrued, during the period for the specified type of restructuring cost.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Nature of Business and Summary of Significant Accounting Policies - Research and Development and Restructuring and Other Special Charges, Net (Details) $ in Millions									3 Months Ended								12 Months Ended
	Aug. 01, 2019 mill facility	Sep. 30, 2018 facility	Aug. 31, 2018 USD ($)	Jun. 12, 2018 facility	Jan. 01, 2018 mill facility	Dec. 01, 2017 folding_carton_facility	Oct. 04, 2017 folding_carton_facility	Jul. 10, 2017 folding_carton_facility	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2022 USD ($) mill	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Segment Reporting Information [Line Items]
Research and development expense																		$ 9.2	$ 8.7	$ 14.4
Number of converting facilities acquired \| facility	2
Number of mills acquired \| mill	1
Term of disposal program																		3 years
Business Combinations, Shutdowns, and Other Special Charges, Net
Charges Associated with Business Combinations																		$ 4.1	46.8	16.2
Shutdown and Other Special Charges																		23.6	6.7	18.6
Exit Activities																		10.2	0.0	0.0
Gain on Sale of Assets																		0.0	(38.6)	(3.7)
Total									$ 13.6	$ 8.2	$ 9.9	$ 6.2	$ 7.4	$ (27.4)	$ 8.6	$ 26.3		37.9	$ 14.9	$ 31.1
Facility Closing
Business Combinations, Shutdowns, and Other Special Charges, Net
Exit Activities									14.9
Forecast \| Facility Closing
Segment Reporting Information [Line Items]
Number of mills expected to close \| mill																	2
Forecast \| Construction-in-Progress
Segment Reporting Information [Line Items]
Investment in new CRB mill																	$ 600.0
Paperboard Mills
Segment Reporting Information [Line Items]
Gain on sale of assets			$ 37.1
Expected restructuring charges									$ 40.0									$ 40.0
Leticia Corporation
Segment Reporting Information [Line Items]
Number of converting facilities acquired \| facility		2
PFP, LLC And PFP Dallas Converting, LLC
Segment Reporting Information [Line Items]
Number of converting facilities acquired \| facility				2
NACP Combination \| Paperboard Mills
Segment Reporting Information [Line Items]
Number of mills \| facility					2
Seydaco Packaging Corp.
Segment Reporting Information [Line Items]
Number of folding carton facilities acquired \| folding_carton_facility						3
Norgraft Packaging
Segment Reporting Information [Line Items]
Number of folding carton facilities acquired \| folding_carton_facility							2
Carton Craft Corporation
Segment Reporting Information [Line Items]
Number of folding carton facilities acquired \| folding_carton_facility								2
UNITED STATES \| Leticia Corporation \| Americas Paperboard Packaging
Segment Reporting Information [Line Items]
Number of converting facilities acquired \| facility		2
UNITED STATES \| PFP, LLC And PFP Dallas Converting, LLC \| Americas Paperboard Packaging
Segment Reporting Information [Line Items]
Number of converting facilities acquired \| facility				2
UNITED STATES \| NACP Combination \| Americas Paperboard Packaging
Segment Reporting Information [Line Items]
Number of mills \| mill					2
Number of converting facilities \| facility					3
UNITED KINGDOM \| NACP Combination \| Europe Paperboard Packaging
Segment Reporting Information [Line Items]
Number of converting facilities \| facility					1