Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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Amount before accumulated depreciation, depletion and amortization of 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, and furniture and fixtures.

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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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No definition available.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Property and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 251,815		$ 251,815		$ 239,244
Less accumulated depreciation	(130,281)		(130,281)		(123,214)
Total property and equipment, net	121,534		121,534		116,030
Depreciation	5,232	$ 3,215	16,070	$ 10,488
Construction and transportation equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	225,887		225,887		217,945
Buildings and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	19,275		19,275		14,641
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	3,891		3,891		3,891
Office equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 2,762		$ 2,762		$ 2,767