Note 4 - Cost and Estimated Earnings on Uncompleted Contracts - Cost and Estimated Earnings on Uncompleted Contracts (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Costs and estimated earnings incurred on uncompleted contracts	$ 278,797	$ 550,823
Less billings to date	(255,069)	(530,119)
Total	23,728	20,704
Costs and estimated earnings in excess of billings on uncompleted contracts	42,130	40,945
Billings in excess of costs and estimated earnings on uncompleted contracts	$ (18,402)	$ (20,241)

The amount of billings to date.

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Amount, before allowance for credit loss, of right to consideration in exchange for good or service transferred to customer, when right is conditioned on something other than passage of time.

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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as current.

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Amount to be collected within one year of the balance sheet date (or one operating cycle, if longer) from customers in accordance with the contractual provisions of long-term contracts or programs including amounts billed and unbilled as of the balance sheet date.

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Unbilled amounts due for services rendered or to be rendered, actions taken or to be taken, or a promise to refrain from taking certain actions in accordance with the terms of a legally binding agreement between the entity and, at a minimum, one other party. An example would be amounts associated with contracts or programs where the recognized revenue for performance thereunder exceeds the amounts billed under the terms thereof as of the date of the balance sheet.

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