CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 26, 2015	Dec. 27, 2014	Dec. 28, 2013
Statement of Comprehensive Income [Abstract]
Net earnings	$ 45,333	$ 189,318	$ 280,460
Foreign currency translation adjustments:
Unrealized translation gains (losses)	(96,694)	(82,275)	(71,698)
Realized loss on sale of investment in foreign entity included in other expense	0	0	5,194
Realized loss on deconsolidation of subsidiary	0	0	8,559
Foreign currency translation adjustments	(96,694)	(82,275)	(57,945)
Unrealized gain/(loss) on cash flow hedge:
Amortization cost included in interest expense	74	594	400
Realized (gain) loss included in net earnings	(3,130)	983	0
Unrealized gain (loss) on cash flow hedge	2,855	4,837	0
Derivative adjustment	(201)	6,414	400
Actuarial gain (loss) in defined benefit pension plan, net of tax expense (benefit) of ($10,732) in 2015, ($3,450) in 2014, and ($10,143) in 2013	(40,274)	(13,709)	(41,282)
Other comprehensive income (loss)	(137,169)	(89,570)	(98,827)
Comprehensive income (loss)	(91,836)	99,748	181,633
Comprehensive loss (income) attributable to noncontrolling interests	(832)	(2,520)	(9,174)
Comprehensive income (loss) attributable to Valmont Industries, Inc.	$ (92,668)	$ 97,228	$ 172,459