Note 4 - Goodwill and Intangible Assets (Details) - Reconciliation Goodwill (USD $)	12 Months Ended				3 Months Ended
	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014
Goodwill [Roll Forward]
Goodwill	$ 348,680,000
Additions to goodwill through acquisitions	100,000	[1],[2]
Goodwill, Impairment Loss	(51,512,000)		0	0
Foreign currency translation	(4,243,000)
Goodwill	293,023,000		348,680,000		293,023,000
Infrastructure Solutions [Member]
Goodwill [Roll Forward]
Goodwill	195,570,000
Additions to goodwill through acquisitions	1,100,000	[1],[2]
Goodwill, Impairment Loss					(29,700,000)
Foreign currency translation	(3,324,000)
Goodwill	177,300,000				177,300,000
Corrosion Protection [Member]
Goodwill [Roll Forward]
Goodwill	75,862,000
Additions to goodwill through acquisitions	0	[1],[2]
Goodwill, Impairment Loss	(35,443,000)
Foreign currency translation	(919,000)
Goodwill	39,500,000				39,500,000
Energy Services [Member]
Goodwill [Roll Forward]
Goodwill	77,248,000
Additions to goodwill through acquisitions	(1,000,000)	[1],[2]
Goodwill, Impairment Loss	0
Foreign currency translation	0
Goodwill	$ 76,248,000				$ 76,248,000

[1] During the second quarter of 2014, the Company recorded goodwill of $1.1 million related to the 2012 acquisition of Fyfe Asia (see Note 1).

[2] During the fourth quarter of 2014, the Company decreased goodwill by $1.0 million related to the 2013 acquisition of Brinderson (see Note 1)