Commitments and Contingent Liabilities (Details Textual) - USD ($) $ in Thousands	Dec. 01, 2018	Mar. 03, 2018
Commitments and Contingencies Disclosure [Abstract]
Company's backlog bonded by performance bonds	$ 224,000
Face value of performance bonds	478,800
Line of Credit Facility [Line Items]
Other non-current liabilities	85,405	$ 70,646
Other assets	40,249	$ 33,674
Purchase obligations	163,200
New Markets Tax Credit
Line of Credit Facility [Line Items]
Other non-current liabilities	3,200
Industrial Revenue Bonds
Line of Credit Facility [Line Items]
Debt	20,400
Letter of credit | Industrial Revenue Bonds
Line of Credit Facility [Line Items]
Debt	$ 25,100