Description of the Business and Basis of Presentation (Policies)	9 Months Ended
Oct. 31, 2012
Description of the Business and Basis of Presentation [Abstract]
Description of the Business	Description of the Business Argan, Inc. (“Argan”) conducts continuing operations through its wholly owned subsidiaries, Gemma Power Systems, LLC and affiliates (“GPS”), which provided over 90% of consolidated net revenues for the periods presented herein, and Southern Maryland Cable, Inc. (“SMC”). Argan and these consolidated subsidiaries are hereinafter referred to as the “Company.” Through GPS, the Company provides a full range of engineering, procurement, construction, commissioning, maintenance and consulting services to the power generation and renewable energy markets in the United States for a wide range of customers including public utilities and independent power project owners. The Company determined that GPS is the primary beneficiary of two variable interest entities that were formed during the year ended January 31, 2012, for the purpose of developing a pair of gas-fired power plants. The combination of GPS and the variable interest entities represents the power industry services business segment. Through SMC, the services of the telecommunications infrastructure services segment include project management, construction, installation and maintenance provided to commercial, local government and federal government customers primarily in the mid-Atlantic region.
Basis of Presentation	Basis of Presentation The consolidated financial statements include the accounts of Argan, its wholly-owned subsidiaries and two variable interest entities for which GPS is deemed to be the primary beneficiary (see Note 3 below). The Company’s fiscal year ends on January 31. All significant inter-company balances and transactions have been eliminated in consolidation. In Note 16, the Company has provided certain financial information relating to the operating results and assets of its industry segments based on the manner in which management disaggregates the Company’s financial reporting for purposes of making internal operating decisions. The condensed consolidated balance sheet as of October 31, 2012, the condensed consolidated statements of operations for the three and nine months ended October 31, 2012 and 2011, and the condensed consolidated statements of cash flows for the nine months ended October 31, 2012 and 2011 are unaudited. The condensed consolidated balance sheet as of January 31, 2012 has been derived from audited financial statements. In the opinion of management, the accompanying condensed consolidated financial statements contain all adjustments, which are of a normal and recurring nature, considered necessary to present fairly the financial position of the Company as of October 31, 2012 and the results of its operations and its cash flows for the interim periods presented. The results of operations for any interim period are not necessarily indicative of the results of operations for any other interim period or for a full fiscal year. These condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and note disclosures normally included in annual financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been condensed or omitted pursuant to those rules and regulations, although the Company believes that the disclosures made are adequate to make the information not misleading. The accompanying condensed consolidated financial statements and notes should be read in conjunction with the consolidated financial statements, the notes thereto (including the summary of significant accounting policies), and the independent registered public accounting firm’s report thereon that are included in the Company’s Annual Report on Form 10-K filed with the SEC for the fiscal year ended January 31, 2012 on April 13, 2012.
Fair Values	Fair Values The carrying value amounts presented in the condensed consolidated balance sheets for the Company’s cash and cash equivalents, accounts receivable and accounts payable are reasonable estimates of their fair values due to the short-term nature of these instruments. The fair value amounts of business segments (as needed for purposes of determining indications of impairment to the carrying value of goodwill) are determined using an average of valuations based on market multiples and discounted cash flows, and consideration of our market capitalization.

Description of the Business and Basis of Presentation (Policies)

9 Months Ended

Oct. 31, 2012

Description of the Business and Basis of Presentation [Abstract]

Description of the Business

Argan, Inc. (“Argan”) conducts continuing operations through its wholly owned subsidiaries, Gemma Power Systems, LLC and affiliates (“GPS”), which provided over 90% of consolidated net revenues for the periods presented herein, and Southern Maryland Cable, Inc. (“SMC”). Argan and these consolidated subsidiaries are hereinafter referred to as the “Company.” Through GPS, the Company provides a full range of engineering, procurement, construction, commissioning, maintenance and consulting services to the power generation and renewable energy markets in the United States for a wide range of customers including public utilities and independent power project owners. The Company determined that GPS is the primary beneficiary of two variable interest entities that were formed during the year ended January 31, 2012, for the purpose of developing a pair of gas-fired power plants. The combination of GPS and the variable interest entities represents the power industry services business segment. Through SMC, the services of the telecommunications infrastructure services segment include project management, construction, installation and maintenance provided to commercial, local government and federal government customers primarily in the mid-Atlantic region.

Basis of Presentation

Basis of Presentation

The consolidated financial statements include the accounts of Argan, its wholly-owned subsidiaries and two variable interest entities for which GPS is deemed to be the primary beneficiary (see Note 3 below). The Company’s fiscal year ends on January 31. All significant inter-company balances and transactions have been eliminated in consolidation. In Note 16, the Company has provided certain financial information relating to the operating results and assets of its industry segments based on the manner in which management disaggregates the Company’s financial reporting for purposes of making internal operating decisions.

The condensed consolidated balance sheet as of October 31, 2012, the condensed consolidated statements of operations for the three and nine months ended October 31, 2012 and 2011, and the condensed consolidated statements of cash flows for the nine months ended October 31, 2012 and 2011 are unaudited. The condensed consolidated balance sheet as of January 31, 2012 has been derived from audited financial statements. In the opinion of management, the accompanying condensed consolidated financial statements contain all adjustments, which are of a normal and recurring nature, considered necessary to present fairly the financial position of the Company as of October 31, 2012 and the results of its operations and its cash flows for the interim periods presented. The results of operations for any interim period are not necessarily indicative of the results of operations for any other interim period or for a full fiscal year.

These condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and note disclosures normally included in annual financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been condensed or omitted pursuant to those rules and regulations, although the Company believes that the disclosures made are adequate to make the information not misleading. The accompanying condensed consolidated financial statements and notes should be read in conjunction with the consolidated financial statements, the notes thereto (including the summary of significant accounting policies), and the independent registered public accounting firm’s report thereon that are included in the Company’s Annual Report on Form 10-K filed with the SEC for the fiscal year ended January 31, 2012 on April 13, 2012.

Fair Values

Fair Values

The carrying value amounts presented in the condensed consolidated balance sheets for the Company’s cash and cash equivalents, accounts receivable and accounts payable are reasonable estimates of their fair values due to the short-term nature of these instruments. The fair value amounts of business segments (as needed for purposes of determining indications of impairment to the carrying value of goodwill) are determined using an average of valuations based on market multiples and discounted cash flows, and consideration of our market capitalization.