GOODWILL AND INTANGIBLE ASSETS (Details 3) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 27, 2014	Dec. 28, 2013
Carrying amount of goodwill
Balance at the beginning of the period	$ 349,632us-gaap_Goodwill	$ 330,791us-gaap_Goodwill
Acquisitions	49,562us-gaap_GoodwillAcquiredDuringPeriod	21,189us-gaap_GoodwillAcquiredDuringPeriod
Foreign currency translation	(14,083)us-gaap_GoodwillTranslationAdjustments	(2,348)us-gaap_GoodwillTranslationAdjustments
Balance at the end of the period	385,111us-gaap_Goodwill	349,632us-gaap_Goodwill
Engineered Infrastructure Products segment:
Carrying amount of goodwill
Balance at the beginning of the period	175,442	155,185
Acquisitions	32,219	21,189
Foreign currency translation	(10,587)	(2,669)
Other		(1,737)
Balance at the end of the period	197,074	175,442
Utility Support Structures segment
Carrying amount of goodwill
Balance at the beginning of the period		77,141
Other		1,737
Balance at the end of the period	75,404	75,404
Coatings segment
Carrying amount of goodwill
Balance at the beginning of the period	77,062	77,053
Foreign currency translation	(2,200)	9
Balance at the end of the period	74,862	77,062
Irrigation segment
Carrying amount of goodwill
Balance at the beginning of the period	2,420	2,517
Acquisitions	17,193
Foreign currency translation	(77)	(97)
Balance at the end of the period	19,536	2,420
Other
Carrying amount of goodwill
Balance at the beginning of the period	19,304	18,895
Foreign currency translation	(1,069)	409
Balance at the end of the period	$ 18,235	$ 19,304

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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