Revenue, Receivables and Contract Assets and Liabilities Accounts Receivable (Details) - USD ($) $ in Thousands	May 30, 2020	Feb. 29, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total receivables	$ 158,500	$ 199,275
Less: allowance for credit losses	(2,196)	(2,469)
Net receivables	156,304	196,806
Trade accounts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total receivables	122,092	141,126
Construction contracts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total receivables	12,630	20,808
Contract retainage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total receivables	$ 23,778	$ 37,341