GOODWILL AND INTANGIBLE ASSETS - Impairment (Details) - USD ($)	Apr. 01, 2017	Dec. 31, 2016
Indefinite-lived Intangible Assets [Line Items]
Goodwill	$ 324,061,000	$ 321,110,000
ESS
Indefinite-lived Intangible Assets [Line Items]
Goodwill	95,079,000	94,314,000
Energy & Mining
Indefinite-lived Intangible Assets [Line Items]
Goodwill	74,158,000	72,212,000
Coatings Segment
Indefinite-lived Intangible Assets [Line Items]
Goodwill	59,696,000	$ 59,569,000
Offshore Structures | Energy & Mining
Indefinite-lived Intangible Assets [Line Items]
Goodwill	$ 13,209