Contracts Revenue, Percent

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- Definition

Number of customers exceeding the 10% benchmark percentage.

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No definition available.

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- Definition

Trade Accounts Receivable and Contract Receivable Retainage, Gross

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No definition available.

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- Definition

Trade Accounts Receivable and Contract Receivable Retainage, Net

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No definition available.

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- Definition

Amount of allowance for credit loss on accounts receivable, classified as current.

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- Definition

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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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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Concentration of Risk and Enterprise Wide Disclosures (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2020 USD ($) customer	Dec. 31, 2019 USD ($) customer	Dec. 31, 2018 USD ($) customer
Concentration Risk [Line Items]
Allowance for credit losses	$ (411)				$ (2,600)				$ (411)	$ (2,600)
Contract revenues	170,176	$ 189,433	$ 183,713	$ 166,620	199,793	$ 199,507	$ 165,985	$ 143,105	$ 709,942	$ 708,390	$ 520,894
Foreign
Concentration Risk [Line Items]
Contract revenues, percent									1.80%	1.60%	2.30%
Customer concentration risk \| Trade and contract retainage receivables
Concentration Risk [Line Items]
Gross receivables	133,265				161,687				$ 133,265	$ 161,687
Allowance for credit losses	(411)				(2,600)				(411)	(2,600)
Net receivables	132,854				159,087				$ 132,854	$ 159,087
Number of customers exceeding the 10% benchmark percentage \| customer									0	0
Concentration risk, percentage									100.00%	100.00%
Customer concentration risk \| Contract revenues
Concentration Risk [Line Items]
Number of customers exceeding the 10% benchmark percentage \| customer										0	0
Concentration risk, percentage									100.00%	100.00%	100.00%
Contract revenues									$ 709,942	$ 708,390	$ 520,894
Customer concentration risk \| Federal Government \| Trade and contract retainage receivables
Concentration Risk [Line Items]
Gross receivables	4,826				4,765				$ 4,826	$ 4,765
Concentration risk, percentage									4.00%	3.00%
Customer concentration risk \| Federal Government \| Contract revenues
Concentration Risk [Line Items]
Concentration risk, percentage									7.00%	6.00%	8.00%
Contract revenues									$ 51,793	$ 46,425	$ 42,143
Customer concentration risk \| State Governments \| Trade and contract retainage receivables
Concentration Risk [Line Items]
Gross receivables					5,864					$ 5,864
Concentration risk, percentage										4.00%
Customer concentration risk \| State Governments \| Contract revenues
Concentration Risk [Line Items]
Concentration risk, percentage									4.00%	7.00%	6.00%
Contract revenues									$ 27,574	$ 47,831	$ 30,470
Customer concentration risk \| Local Governments \| Trade and contract retainage receivables
Concentration Risk [Line Items]
Gross receivables	17,823				41,944				$ 17,823	$ 41,944
Concentration risk, percentage									13.00%	26.00%
Customer concentration risk \| Local Governments \| Contract revenues
Concentration Risk [Line Items]
Number of customers exceeding the 10% benchmark percentage \| customer									1
Concentration risk, percentage									29.00%	30.00%	21.00%
Contract revenues									$ 202,839	$ 212,958	$ 107,478
Customer concentration risk \| Local Governments \| Contract revenues \| Customer One
Concentration Risk [Line Items]
Concentration risk, percentage									11.40%
Customer concentration risk \| Private Companies \| Trade and contract retainage receivables
Concentration Risk [Line Items]
Gross receivables	$ 110,616				$ 109,114				$ 110,616	$ 109,114
Concentration risk, percentage									83.00%	67.00%
Customer concentration risk \| Private Companies \| Contract revenues
Concentration Risk [Line Items]
Concentration risk, percentage									60.00%	57.00%	65.00%
Contract revenues									$ 427,736	$ 401,176	$ 340,803