Business and basis of Presentation.

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Number of manufacturing facility.

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Payment made to investment in joint venture from proceeds from sale of business.

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Potential adjustments to the purchase price consideration.

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Potential proceeds from sale of businesses.

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Receivable from sale of business.

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Revised maximum potential adjustment to purchase price consideration.

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Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer), including liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received, taxes, interest, rent and utilities, accrued salaries and bonuses, payroll taxes and fringe benefits.

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

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Dividends received on equity and other investments during the current period.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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-Topic 230
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Business (Narrative) (Details) $ in Millions		1 Months Ended	3 Months Ended	12 Months Ended
Business (Narrative) (Details) $ in Millions	Jul. 18, 2018 USD ($)	Jan. 31, 2017 Facility	Sep. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Nov. 17, 2017 USD ($)
Business And Basis Of Presentation [Line Items]
Potential adjustments to the purchase price consideration	$ 35.0
Potential adjustments to the purchase price consideration	20.0
Proceeds from sale of business				$ 330.0
Payment to WAVE from Knauf proceeds				70.0
Account payable and accrued expenses related to investment in joint venture				$ 383.3	$ 108.4
Tectum, Inc. [Member]
Business And Basis Of Presentation [Line Items]
Number of manufacturing facility \| Facility		2
August 1, 2018 [Member] \| Knauf [Member]
Business And Basis Of Presentation [Line Items]
Receivable from sale of business	250.0
Proceeds from sale of business			$ 250.0
September 15, 2018 [Member] \| Knauf [Member]
Business And Basis Of Presentation [Line Items]
Receivable from sale of business	$ 80.0
Proceeds from sale of business			$ 80.0
EMEA and Pacific Rim Business [Member]
Business And Basis Of Presentation [Line Items]
Consideration to be received in connection with sale of businesses						$ 330.0
WAVE [Member]
Business And Basis Of Presentation [Line Items]
Equity interest percentage				50.00%
Payment to WAVE from Knauf proceeds				$ 70.0
Account payable and accrued expenses related to investment in joint venture				22.4
WAVE [Member] \| Worthington [Member]
Business And Basis Of Presentation [Line Items]
Dividend received from joint venture				$ 35.0