Note 5 - Accounts Receivable, Net - Components of Accounts Receivable, Net (Details) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Accounts receivable $ 77,503 $ 49,283
Less: allowance for doubtful accounts (1,992) (1,536)
Accounts receivable, net 75,511 47,747
Billed [Member]    
Accounts receivable 53,756 32,806
Unbilled [Member]    
Accounts receivable 23,237 15,678
Contract Retentions [Member]    
Accounts receivable $ 510 $ 799