CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net earnings	$ 42,346	$ 34,680	$ 79,801	$ 75,160
Foreign currency translation adjustments:
Unrealized translation gain	1,049	(46,953)	3,315	(40,149)
Realized loss on divestiture of grinding media business recorded in earnings	0	9,203	0	9,203
Gain (loss) on hedging activities:
Net investment hedges	711	2,396	780	1,607
Realized loss on net investment hedge for grinding media business recorded in earnings	0	1,215	0	1,215
Amortization cost included in interest expense	(16)	25	(32)	44
Deferred loss on interest rate hedges	0	(2,467)	0	(2,467)
Commodity hedges	(2,109)	1,438	(2,109)	1,345
Cross currency swaps	(3,933)	0	(1,672)	0
Other comprehensive income	(4,298)	(35,143)	282	(29,202)
Comprehensive income	38,048	(463)	80,083	45,958
Comprehensive income attributable to noncontrolling interests	(983)	(1,114)	(2,092)	(5,861)
Comprehensive income attributable to Valmont Industries, Inc.	$ 37,065	$ (1,577)	$ 77,991	$ 40,097