GOODWILL AND INTANGIBLE ASSETS (Details 3) (USD $) In Thousands, unless otherwise specified	12 Months Ended							12 Months Ended
	Dec. 29, 2012	Dec. 31, 2011	Dec. 29, 2012 Engineered Infrastructure Products segment:	Dec. 31, 2011 Engineered Infrastructure Products segment:	Dec. 29, 2012 Utility Support Structures segment	Dec. 31, 2011 Utility Support Structures segment	Dec. 25, 2010 Utility Support Structures segment	Dec. 29, 2012 Coatings segment	Dec. 31, 2011 Coatings segment	Dec. 29, 2012 Irrigation segment	Dec. 31, 2011 Irrigation segment	Dec. 29, 2012 Other	Dec. 31, 2011 Other
Carrying amount of goodwill
Balance at the beginning of the period	$ 314,662	$ 314,847	$ 151,558	$ 152,062	$ 77,141	$ 77,141	$ 77,141	$ 64,820	$ 64,868	$ 2,576	$ 2,064	$ 18,567	$ 18,712
Impairment		(276)									(276)
Acquisition	12,676	788						12,676			788
Foreign currency translation	3,453	(697)	3,627	(504)				(443)	(48)	(59)		328	(145)
Balance at the end of the period	$ 330,791	$ 314,662	$ 155,185	$ 151,558	$ 77,141	$ 77,141	$ 77,141	$ 77,053	$ 64,820	$ 2,517	$ 2,576	$ 18,895	$ 18,567