Disposal Group, Number Of Asphalt Terminals

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Tax Cuts And Jobs Act of 2017,Reclassification From AOCI To Retained Earnings, Tax Effect

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Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

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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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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 distribution received from equity method investee for return of investment, classified as investing activities. Excludes distribution for return on investment, classified as operating activities.

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The cash inflow associated with the sale of equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

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The cumulative amount of the reporting entity's undistributed earnings or deficit.

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Organization and Basis of Presentation (Details) $ in Millions			6 Months Ended
	May 21, 2018 USD ($) asphalt_terminal	Jan. 01, 2018 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Mar. 16, 2018 USD ($)	Feb. 12, 2018 USD ($) asphalt_terminal	Dec. 31, 2017 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of equity method investment	$ 110.8
Tax Cuts And Jobs Act of 2017, reclassification from AOCI to retained earnings, tax effect		$ 1.6
Retained earnings			$ (742.8)				$ (767.8)
Distribution from equity method investments			$ 0.7	$ 10.6
California Discontinued Entities
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration of business disposition					$ 85.9
Four Asphalt Terminals [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number Of Asphalt Terminals \| asphalt_terminal	4					4
Consideration of business disposition						$ 75.0
Paramount-Nevada Asphalt Company, LLC [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Equity method investment, ownership percentage (as percent)	50.00%					50.00%
Restatement Adjustment \| Accounting Standards Update 2016-16
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Retained earnings		$ 29.9