Description of Business and Basis of Presentation	9 Months Ended
Sep. 30, 2011
1. Description of Business and Basis of Presentation [Abstract]
Business Description and Basis of Presentation	Description of Business and Basis of Presentation Description of Business Orion Marine Group, Inc. and its subsidiaries (hereafter collectively referred to as “Orion” or the “Company”) provide a broad range of marine construction services on, over and under the water along the Gulf Coast, the Atlantic Seaboard, the West Coast and the Caribbean Basin. Our heavy civil marine projects include marine transportation facilities; bridges and causeways; marine pipelines; mechanical and hydraulic dredging and specialty projects. We are headquartered in Houston, Texas. Although we describe our business in this report in terms of the services we provide, our base of customers and the geographic areas in which we operate, we have concluded that our operations comprise one reportable segment pursuant to Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 280 – Segment Reporting. In making this determination, we considered that each project has similar characteristics, includes similar services, has similar types of customers and is subject to the same regulatory environment. We organize, evaluate and manage our financial information around each project when making operating decisions and assessing our overall performance. Basis of Presentation The accompanying condensed consolidated financial statements and financial information included herein have been prepared pursuant to the interim period reporting requirements of Form 10-Q. Consequently, certain information and note disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States have been condensed or omitted. Readers of this report should also read our consolidated financial statements and the notes thereto included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2010 (“2010 Form 10-K”) as well as Item 7 – Management’s Discussion and Analysis of Financial Condition and Results of Operations also included in our 2010 Form 10-K. In the opinion of management, the accompanying unaudited condensed consolidated financial statements contain all adjustments considered necessary for a fair presentation of the Company’s financial position, results of operations and cash flows for the periods presented. Such adjustments are of a normal recurring nature. Interim results of operations for the three and nine months ended September 30, 2011, are not necessarily indicative of the results that may be expected for the year ending December 31, 2011. Current Year Presentation Certain reclassifications have been made to prior year’s financial statements to conform to the current year presentation. These reclassifications were related to the inclusion of financing cost amortization as a component of interest expense and not selling, general and administrative expenses and had no effect on previously reported net income or retained earnings.

Description of Business and Basis of Presentation

Description of Business

Orion Marine Group, Inc. and its subsidiaries (hereafter collectively referred to as “Orion” or the “Company”) provide a broad range of marine construction services on, over and under the water along the Gulf Coast, the Atlantic Seaboard, the West Coast and the Caribbean Basin. Our heavy civil marine projects include marine transportation facilities; bridges and causeways; marine pipelines; mechanical and hydraulic dredging and specialty projects. We are headquartered in Houston, Texas.

Although we describe our business in this report in terms of the services we provide, our base of customers and the geographic areas in which we operate, we have concluded that our operations comprise one reportable segment pursuant to Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 280 – Segment Reporting. In making this determination, we considered that each project has similar characteristics, includes similar services, has similar types of customers and is subject to the same regulatory environment. We organize, evaluate and manage our financial information around each project when making operating decisions and assessing our overall performance.

Basis of Presentation

The accompanying condensed consolidated financial statements and financial information included herein have been prepared pursuant to the interim period reporting requirements of Form 10-Q. Consequently, certain information and note disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States have been condensed or omitted. Readers of this report should also read our consolidated financial statements and the notes thereto included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2010 (“2010 Form 10-K”) as well as Item 7 – Management’s Discussion and Analysis of Financial Condition and Results of Operations also included in our 2010 Form 10-K.

In the opinion of management, the accompanying unaudited condensed consolidated financial statements contain all adjustments considered necessary for a fair presentation of the Company’s financial position, results of operations and cash flows for the periods presented. Such adjustments are of a normal recurring nature. Interim results of operations for the three and nine months ended September 30, 2011, are not necessarily indicative of the results that may be expected for the year ending December 31, 2011.

Current Year Presentation

Certain reclassifications have been made to prior year’s financial statements to conform to the current year presentation. These reclassifications were related to the inclusion of financing cost amortization as a component of interest expense and not selling, general and administrative expenses and had no effect on previously reported net income or retained earnings.