Costs and Estimated Earnings Related to Billings on Uncompleted Contracts (Details) (USD $) In Thousands, unless otherwise specified	Aug. 31, 2012	Feb. 29, 2012
Costs and Estimated Earnings Related to Billings on Uncompleted Contracts
Costs incurred to date on uncompleted contracts	$ 10,615	$ 7,499
Estimated earnings recognized to date on these contracts	6,592	4,373
Costs incurred and Estimated earnings of uncompleted contracts	17,207	11,872
Billings to date	(15,327)	(8,978)
Costs and estimated earnings in excess of billings, net	1,880	2,894
Costs and estimated earnings in excess of billings	2,214	3,236
Billings in excess of cost and estimated earnings	$ (334)	$ (342)