Condensed Consolidated Statements of Operations (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Contract revenues	$ 81,455us-gaap_ContractsRevenue	$ 81,258us-gaap_ContractsRevenue
Costs of contract revenues	72,999us-gaap_ContractRevenueCost	73,611us-gaap_ContractRevenueCost
Gross profit	8,456us-gaap_GrossProfit	7,647us-gaap_GrossProfit
Selling, general and administrative expenses	8,692	7,964
Loss from operations	(236)us-gaap_OperatingIncomeLoss	(317)us-gaap_OperatingIncomeLoss
Other (expense) income
Gain from sale of assets, net	43us-gaap_GainLossOnDispositionOfAssets1	93us-gaap_GainLossOnDispositionOfAssets1
Interest income	12	10
Interest expense	(238)us-gaap_InterestExpense	(130)us-gaap_InterestExpense
Other expense, net	(183)us-gaap_OtherNonoperatingIncomeExpense	(27)us-gaap_OtherNonoperatingIncomeExpense
Loss before income taxes	(419)	(344)
Income tax benefit	(161)us-gaap_IncomeTaxExpenseBenefit	(134)us-gaap_IncomeTaxExpenseBenefit
Net loss attributable to Orion common stockholders	$ (258)us-gaap_NetIncomeLoss	$ (210)us-gaap_NetIncomeLoss
Basic loss per share (in dollars per share)	$ (0.01)us-gaap_EarningsPerShareBasic	$ (0.01)us-gaap_EarningsPerShareBasic
Diluted loss per share (in dollars per share)	$ (0.01)us-gaap_EarningsPerShareDiluted	$ (0.01)us-gaap_EarningsPerShareDiluted
Shares used to compute loss per share
Basic (shares)	27,604,681	27,397,877
Diluted (shares)	27,604,681	27,397,877

Costs incurred and are directly related to generating contract revenues.

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Revenue earned during the period arising from products sold or services provided under the terms of a contract, not elsewhere specified in the taxonomy. May include government contracts, construction contracts, and any other contract related to a particular project or product.

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee.

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Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the cost of borrowed funds accounted for as interest expense.

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Interest income derived from funds deposited with both domestic and foreign financial institutions including funds in money market and other accounts.

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The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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