Commitments and Contingent Liabilities (Details Textual) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Nov. 30, 2013	Dec. 01, 2012
Commitments and Contingencies Disclosure [Abstract]
Company's backlog bonded by performance bonds	$ 83,200
Face value of performance bonds	240,300
Total value of letter of credit	23,500
Line of Credit Facility, Maximum Borrowing Capacity	100,000
Purchase obligations	75,400
Derivative, Notional Amount	18,600
Derivative Asset, Fair Value, Net	300
Proceeds from new markets tax credit transaction, net of deferred costs	7,752	0
Gross proceeds from new markets tax credits	10,700
Deferred Costs	$ 3,000