GOODWILL AND INTANGIBLE ASSETS (Details 4) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Dec. 26, 2015	Sep. 26, 2015	Jun. 27, 2015	Dec. 26, 2015	Dec. 27, 2014
Carrying amount of goodwill
Balance at the beginning of the period				$ 385,111	$ 349,632
Impairment	$ (7,100)			(34,892)
Acquisition				3,019	49,412
Foreign currency translation				(14,585)	(13,933)
Divestiture of business				(1,737)
Balance at the end of the period	336,916			336,916	385,111
Engineered Support Structures
Carrying amount of goodwill
Balance at the beginning of the period				107,868	97,253
Impairment				0
Acquisition				0	15,416
Foreign currency translation				(4,856)	(4,801)
Divestiture of business			$ (1,737)	(1,737)
Balance at the end of the period	101,275			101,275	107,868
Energy and Mining Segment
Carrying amount of goodwill
Balance at the beginning of the period				106,770	96,759
Impairment	(18,670,000)			(18,670)
Acquisition				0	16,803
Foreign currency translation				(6,941)	(6,792)
Divestiture of business				0
Balance at the end of the period	81,159			81,159	106,770
Utility Support Structures Segment
Carrying amount of goodwill
Balance at the beginning of the period				75,404	75,404
Impairment				0
Acquisition				0	0
Foreign currency translation				0	0
Divestiture of business				0
Balance at the end of the period	75,404			75,404	75,404
Coatings Segment
Carrying amount of goodwill
Balance at the beginning of the period				75,533	77,796
Impairment	(7,122)	$ (9,100)		(16,222)
Acquisition				3,019	0
Foreign currency translation				(2,611)	(2,263)
Divestiture of business				0
Balance at the end of the period	59,719			59,719	75,533
Irrigation Segment
Carrying amount of goodwill
Balance at the beginning of the period				19,536	2,420
Impairment				0
Acquisition				0	17,193
Foreign currency translation				(177)	(77)
Divestiture of business				0
Balance at the end of the period	$ 19,359			$ 19,359	$ 19,536