Goodwill and Intangible Assets - Schedule of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Feb. 28, 2018	Feb. 28, 2017
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 306,579	$ 292,527
Acquisitions	14,066	13,386
Foreign Exchange Translation	662	666
Goodwill, ending balance	321,307	306,579
Galvanizing Services [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	109,980	109,314
Acquisitions	6,590	0
Foreign Exchange Translation	662	666
Goodwill, ending balance	117,232	109,980
Energy [Member]
Goodwill [Roll Forward]
Goodwill, beginning balance	196,599	183,213
Acquisitions	7,476	13,386
Foreign Exchange Translation	0	0
Goodwill, ending balance	$ 204,075	$ 196,599