Note 12 - Segment and Geographic Information (Details) - Financial Information by Segment (USD $) In Thousands, unless otherwise specified	3 Months Ended												12 Months Ended
	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Revenues:
Revenues	$ 352,181	[1]	$ 350,138	[2]	$ 322,868	$ 306,234	$ 315,679	[3]	$ 307,665	[3]	$ 242,100	$ 225,976	$ 1,331,421	[4]	$ 1,091,420	[4]	$ 1,016,831	[4]
Operating income (loss):													44,312		40,329		37,658
Operating income (loss)	(35,631)	[1]	(13,934)	[2]	20,619	9,134	22,209	[3]	22,032	[3]	15,823	6,818	(19,812)		66,882		81,803
Assets
Assets	1,295,673						1,377,418						1,295,673		1,377,418		1,217,894
Capital expenditures:
Payments to Acquire Property, Plant, and Equipment													32,899		26,085		44,738
Infrastructure Solutions [Member]
Revenues:
Revenues													567,205		529,301		502,856
Operating income (loss):													15,726		16,552		17,800
Operating income (loss)													(6,194)		28,487		21,809
Assets
Assets	485,785						514,778						485,785		514,778		531,124
Capital expenditures:
Payments to Acquire Property, Plant, and Equipment													13,096		8,828		7,848
Corrosion Protection [Member]
Revenues:
Revenues													458,409		453,886		513,975
Operating income (loss):													19,259		18,736		18,175
Operating income (loss)													(31,010)		37,253		59,994
Assets
Assets	506,659						547,280						506,659		547,280		569,109
Capital expenditures:
Payments to Acquire Property, Plant, and Equipment													12,107		14,399		34,796
Corporate and Other [Member]
Revenues:
Operating income (loss):													2,323		1,823		1,683
Assets
Assets	105,371						116,316						105,371		116,316		101,851
Capital expenditures:
Payments to Acquire Property, Plant, and Equipment													3,976		1,890		2,094
Discontinued Operations [Member]
Assets
Assets	0						8,356						0		8,356		15,810
Energy Services [Member]
Revenues:
Revenues													305,807		108,233		0
Operating income (loss):													7,004		3,218		0
Operating income (loss)													17,392		1,142		0
Assets
Assets	197,858						190,688						197,858		190,688		0
Capital expenditures:
Payments to Acquire Property, Plant, and Equipment													$ 3,720		$ 968		$ 0

[1] Includes expenses of $9.5 million related to our 2014 Restructuring Plan and $52.7 million related to certain goodwill and definite-lived intangible asset impairments (see Notes 2, 3 and 5).

[2] Includes expenses of $40.0 million related to our 2014 Restructuring Plan (see Note 3).

[3] Includes the financial results of Brinderson, which was acquired in July 2013 (see Note 1).

[4] Revenues and long-lived assets are attributed to the country of origin for the Company’s legal entities. For a significant majority of its legal entities, the country of origin relates to the country or geographic area that it services.