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		6 Months Ended
Property and Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 249,207		$ 249,207		$ 239,244
Less accumulated depreciation	(129,611)		(129,611)		(123,214)
Total property and equipment, net	119,596		119,596		116,030
Depreciation	5,390	$ 3,571	10,838	$ 7,273
Construction and transportation equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	225,440		225,440		217,945
Buildings and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	17,267		17,267		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	$ 2,609		$ 2,609		$ 2,767