GOODWILL AND INTANGIBLE ASSETS (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 28, 2015	Dec. 27, 2014
Carrying amount of goodwill
Balance at the beginning of the period	$ 385,111
Foreign currency translation	(11,223)
Balance at the end of the period	373,888
Engineered Infrastructure Products segment:
Carrying amount of goodwill
Balance at the beginning of the period	197,074
Foreign currency translation	(8,654)
Balance at the end of the period	188,420
Utility Support Structures segment
Carrying amount of goodwill
Balance at the beginning of the period		75,404
Balance at the end of the period	75,404	75,404
Coatings segment
Carrying amount of goodwill
Balance at the beginning of the period	74,862
Foreign currency translation	(1,667)
Balance at the end of the period	73,195
Irrigation segment
Carrying amount of goodwill
Balance at the beginning of the period	19,536
Foreign currency translation	(89)
Balance at the end of the period	19,447
Other
Carrying amount of goodwill
Balance at the beginning of the period	18,235
Foreign currency translation	(813)
Balance at the end of the period	$ 17,422