Note 7 - Receivables, Net (Tables)

12 Months Ended

Dec. 31, 2021

Notes Tables

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

December 31,		2021		2020
Contracts completed and in progress:
Billed	$	236,053	$	220,621
Unbilled		126,371		120,144
Total contracts completed and in progress		362,424		340,765
Material sales		43,746		47,067
Other		59,496		51,382
Total gross receivables		465,666		439,214
Less: allowance for credit losses		1,078		1,656
Total net receivables	$	464,588	$	437,558