Description of Business	3 Months Ended
Description of Business	Jun. 30, 2011
Description of Business [Abstract]
DESCRIPTION OF BUSINESS	NOTE A — DESCRIPTION OF BUSINESS *Organization* The Company includes Orion Energy Systems, Inc., a Wisconsin corporation, and all consolidated subsidiaries. The Company is a developer, manufacturer and seller of lighting and energy management systems and a seller and integrator of renewable energy technologies to commercial and industrial businesses, predominantly in North America. In August 2009, the Company created Orion Engineered Systems, a new operating division offering additional alternative renewable energy systems. During the quarter ended December 31, 2010, the new division exceeded the thresholds for segment reporting and, accordingly, the Company introduced the presentation of operating segments in that quarter. See Note I “Segment Reporting” of these financial statements for further discussion of our reportable segments. The Company’s corporate offices and manufacturing operations are located in Manitowoc, Wisconsin and an operations facility occupied by Orion Engineered Systems is located in Plymouth, Wisconsin.

The entire disclosure for organization, consolidation and basis of presentation of financial statements disclosure.

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