DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION (Policies)	6 Months Ended
	Jul. 31, 2016
DESCRIPTION OF THE BUSINESS AND BASIS OF PRESENTATION
Description of the Business	Description of the Business The condensed consolidated financial statements include the accounts of Argan, Inc. (“Argan”), its wholly owned subsidiaries, its majority-controlled joint ventures and any variable interest entities for which Argan or one of its wholly-owned subsidiaries is deemed to be the primary beneficiary. Argan conducts operations through its wholly owned subsidiaries, Gemma Power Systems, LLC and affiliates (“GPS”), which provided 84% and 95% of consolidated revenues for the six months ended July 31, 2016 and 2015, respectively; The Roberts Company (“TRC”); Atlantic Projects Company Limited and affiliates (“APC”) and Southern Maryland Cable, Inc. (“SMC”). Argan and these consolidated subsidiaries are hereinafter cumulatively referred to as the “Company.” Through GPS and APC, the Company provides a full range of engineering, procurement, construction, commissioning, operations management, maintenance, development, technical and consulting services to the power generation and renewable energy markets for a wide range of customers including independent power project owners, public utilities, power plant equipment suppliers and global energy plant construction firms. GPS, including its consolidated joint ventures and variable interest entities, and APC represent our power industry services reportable segment. Through TRC, the industrial fabrication and field services reportable segment produces, delivers and installs fabricated steel components specializing in pressure vessels, heat exchangers and piping systems for industrial plants primarily located in the southern United States. In addition, TRC includes a plant services group that handles maintenance turnarounds, shutdowns and emergency mobilizations. Through SMC, the telecommunications infrastructure services segment provides project management, construction, installation and maintenance services to commercial, local government and federal government customers primarily in the mid-Atlantic region.
Basis of Presentation	Basis of Presentation In Note 16, the Company has provided certain financial information relating to the operating results and assets of its reportable segments based on the manner in which management disaggregates the Company’s financial reporting for purposes of making internal operating decisions. All significant inter-company balances and transactions have been eliminated in consolidation. The Company’s fiscal year ends on January 31 of each year. The condensed consolidated balance sheet as of July 31, 2016, the condensed consolidated statements of earnings for the three and six months ended July 31, 2016 and 2015, and the condensed consolidated statements of cash flows for the six months ended July 31, 2016 and 2015 are unaudited. The condensed consolidated balance sheet as of January 31, 2016 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 July 31, 2016, and its earnings and 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 (“US GAAP”) 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 for the fiscal year ended January 31, 2016.
Revenue Recognition	Revenue Recognition — Revenues are recognized primarily under various construction contracts, including contracts for which revenues are based on either a fixed price, cost-plus-fee or time and materials basis, with typical durations of three months to three years. Revenues from fixed price construction contracts, including a portion of estimated profit, are recognized as services are provided, based on costs incurred and estimated total contract costs using the percentage of completion method. Revenues from cost-plus-fee construction contracts are recognized on the basis of costs incurred during the period plus the fee earned, measured using the cost-to-cost method. Revenues from time and materials contracts are recognized when the related services are provided to the customer. Changes to total estimated contract costs or losses, if any, are recognized in the period in which they are determined. Unapproved change orders, which represent contract variations for which the Company has project owner approval for scope changes but not for the price associated with the scope changes, are reflected in revenues when it is probable that the applicable costs will be recovered through a change in the contract price. The total amount of unapproved change orders included in the total contract value amounts used to determine revenues as of July 31, 2016 was $4.0 million. Disputed change orders that are unapproved in regard to both scope and price are considered claims. The Company recognizes revenues related to a claim only when an agreement on the amount has been reached with the project owner. The Company’s long-term contracts typically have schedule dates and other performance obligations that if not achieved could subject the Company to penalties for liquidated damages. These contract requirements generally relate to specified activities that must be completed by an established date or by achievement of a specified level of output or efficiency. Each contract defines the conditions under which a project owner may make a claim for liquidated damages. However, in some instances, liquidated damages are not asserted by the project owner, but the potential to do so is used in the negotiation or settlement of claims and the closing-out of the contract. During the three months ended July 31, 2016, the Company reached a settlement regarding $12.9 million in liquidated damages related to one project. As of July 31, 2016, it is no longer subject to these liquidated damages. In general, the Company considers potential liquidated damages, the costs of other related items and potential mitigating factors in determining the adequacy of its estimates of completed contract costs.
Fair Values	Fair Values — The carrying value amounts presented in the condensed consolidated balance sheets for the Company’s cash and cash equivalents, short-term investments, accounts receivable, notes 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 identifying indications of impairment to goodwill) are determined by averaging valuations that are calculated using several market-based and income-based approaches deemed appropriate in the circumstances (see Note 8).

Disclosure of accounting policy for revenue recognition. If the entity has different policies for different types of revenue transactions, the policy for each material type of transaction is generally disclosed. If a sales transaction has multiple element arrangements (for example, delivery of multiple products, services or the rights to use assets) the disclosure may indicate the accounting policy for each unit of accounting as well as how units of accounting are determined and valued. The disclosure may encompass important judgment as to appropriateness of principles related to recognition of revenue. The disclosure also may indicate the entity's treatment of any unearned or deferred revenue that arises from the transaction.