Note 8 - Receivables, Net (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]

			As Restated
December 31,	2019		2018
Contracts completed and in progress:
Billed	$	299,633	$	285,230
Unbilled		149,696		98,755
Total contracts completed and in progress		449,329		383,985
Material sales		42,936		45,286
Other		55,526		55,810
Total gross receivables		547,791		485,081
Less: allowance for doubtful accounts		374		328
Total net receivables	$	547,417	$	484,753