Note 15 - Income Taxes - Summary of Current and Noncurrent Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Costs and estimated earnings in excess of billings on uncompleted contracts, net	$ 1,270	$ 2,888
Accrued employee benefits	5,025	5,946
Inventories	563	2,618
Trade receivable, net	199	266
Net operating loss carryforwards	15,637	7,843
Tax credit carryforwards	5,069	4,791
Other assets	1,830	2,737
Other	1,018	520
Deferred tax assets, gross	30,611	27,609
Valuation allowance	(8,217)	(7,057)
Deferred tax assets, net	22,394	20,552
Property and equipment	(22,380)	(24,229)
Intangible assets	(819)	(980)
Prepaid expenses	(477)	(467)
Total deferred tax liabilities	(23,676)	(25,676)
Net deferred income tax liabilities	$ (1,282)	$ (5,124)