CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2020	Mar. 30, 2019
Statement of Comprehensive Income [Abstract]
Net earnings	$ 42,721	$ 37,078
Foreign currency translation adjustments:
Unrealized translation gain (loss)	(49,381)	2,266
Gain (loss) on hedging activities:
Net investment hedges	8,711	69
Cash flow hedges	443	0
Amortization cost included in interest expense	(16)	(16)
Cross currency swaps	(6,302)	(2,261)
Other comprehensive income (loss)	(33,941)	4,580
Comprehensive income	8,780	41,658
Comprehensive income attributable to noncontrolling interests	(297)	(1,109)
Comprehensive income attributable to Valmont Industries, Inc.	$ 8,483	$ 40,549