Commitments and Contingent Liabilities (Details Textual) - USD ($) $ in Thousands	Aug. 31, 2019	Mar. 02, 2019
Commitments and Contingencies Disclosure [Abstract]
Face value of performance bonds	$ 695,700
Line of Credit Facility [Line Items]
Project related liability	34,200	$ 42,800
Other non-current liabilities	79,128	77,182
Other assets	45,004	$ 46,380
Purchase obligations	124,200
Industrial Revenue Bonds
Line of Credit Facility [Line Items]
Debt	$ 20,400