Commitments and Contingent Liabilities (Details Textual) - USD ($) $ in Thousands	Jun. 01, 2019	Mar. 02, 2019
Commitments and Contingencies Disclosure [Abstract]
Company's backlog bonded by performance bonds	$ 306,300
Face value of performance bonds	638,900
Line of Credit Facility [Line Items]
Project related liability	38,000	$ 42,800
Other non-current liabilities	78,712	77,182
Other assets	45,003	$ 46,380
Purchase obligations	132,700
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