Note 7 - Segment Information - Segment Information Report of Statements of Operations (Details) - USD ($) $ in Thousands		3 Months Ended			9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Water Transmission Group [Member] | Operating Segments [Member]
Net sales:
Net Sales		$ 41,075		$ 39,792	$ 110,208	$ 134,479
Gross profit (loss):
Gross profit (loss)		2,939		(725)	(4,083)	8,049
Operating income (loss):
Operating Income (loss)	[1]	1,363		(2,384)	(8,541)	(2,566)
Tubular Products [Member] | Operating Segments [Member]
Net sales:
Net Sales		13		12,543	6,869	56,567
Gross profit (loss):
Gross profit (loss)		(816)		(1,786)	(1,393)	(9,262)
Operating income (loss):
Operating Income (loss)		(802)		(2,298)	(1,700)	(11,169)
Corporate Segment [Member]
Operating income (loss):
Operating Income (loss)		(2,624)		(2,602)	(8,111)	(9,959)
Net Sales		41,088	$ 52,335	52,335	117,077	191,046
Gross profit (loss)		2,123	(2,511)	(2,511)	(5,476)	(1,213)
Operating Income (loss)		$ (2,063)	$ (7,284)	$ (7,284)	$ (18,352)	$ (23,694)

[1] Operating loss for the Water Transmission Group for the nine months ended September 30, 2015 includes the write-off of Water Transmission goodwill of $5.3 million in the second quarter of 2015.