Commitments and Contingent Liabilities (Details Textual) - USD ($) $ in Thousands	Sep. 01, 2018	Mar. 03, 2018
Commitments and Contingencies Disclosure [Abstract]
Company's backlog bonded by performance bonds	$ 246,200
Face value of performance bonds	538,400
Line of Credit Facility [Line Items]
Other non-current liabilities	81,746	$ 70,646
Other assets	41,745	$ 33,674
Purchase obligations	183,100
New Markets Tax Credit
Line of Credit Facility [Line Items]
Other non-current liabilities	6,600
Other assets	500
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	$ 23,500