Number of production facilities acquired.

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Number of warehousing facilities acquired.

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Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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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Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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Face (par) amount of debt instrument at time of issuance.

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase (decrease) of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase.

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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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Acquisitions Additional Information (Details) $ in Millions			3 Months Ended	6 Months Ended
Acquisitions Additional Information (Details) $ in Millions	Nov. 30, 2016 USD ($) facility	Aug. 29, 2016 USD ($) facility	Mar. 31, 2017 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)
Business Acquisition [Line Items]
Goodwill				$ 731.1	$ 737.9
TimBar Corporation
Business Acquisition [Line Items]
Number of corrugated products production facilities acquired \| facility		6
Cash purchase price		$ 385.6
Debt instrument, face amount		$ 385.0
Debt instrument, term		5 years
Adjustment to increase (decrease) goodwill			$ (1.1)	(1.1)
Purchase price			$ 384.5
Acquired finite-lived intangible assets, weighted average useful life		14 years 2 months 12 days
Columbus Container Inc
Business Acquisition [Line Items]
Number of corrugated products production facilities acquired \| facility	1
Number of corrugated products warehousing facilities acquired \| facility	5
Cash purchase price	$ 99.7
Adjustment to increase (decrease) goodwill				$ (5.7)
Acquired finite-lived intangible assets, weighted average useful life	14 years 1 month 6 days
Minimum \| TimBar Corporation
Business Acquisition [Line Items]
Property, plant and equipment useful life		2 years
Minimum \| Columbus Container Inc
Business Acquisition [Line Items]
Property, plant and equipment useful life	1 year
Maximum \| TimBar Corporation
Business Acquisition [Line Items]
Property, plant and equipment useful life		24 years
Maximum \| Columbus Container Inc
Business Acquisition [Line Items]
Property, plant and equipment useful life	32 years