CONDENSED CONSOLIDATED STATEMENTS OF EARNINGS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 25, 2016	Jun. 27, 2015	Jun. 25, 2016	Jun. 27, 2015
Income Statement [Abstract]
Product sales	$ 570,762	$ 611,782	$ 1,103,702	$ 1,215,676
Services sales	69,487	70,341	133,152	136,845
Net sales	640,249	682,123	1,236,854	1,352,521
Product cost of sales	418,072	461,173	811,564	920,714
Services cost of sales	47,060	51,402	89,204	96,805
Total cost of sales	465,132	512,575	900,768	1,017,519
Gross profit	175,117	169,548	336,086	335,002
Selling, general and administrative expenses	103,311	115,548	201,915	223,319
Operating income	71,806	54,000	134,171	111,683
Other income (expenses):
Interest expense	(11,122)	(11,232)	(22,176)	(22,360)
Interest income	707	616	1,518	1,490
Other	1,252	(28)	(426)	988
Total other income (expenses)	(9,163)	(10,644)	(21,084)	(19,882)
Earnings before income taxes	62,643	43,356	113,087	91,801
Income tax expense (benefit):
Current	22,745	19,136	33,259	30,910
Deferred	(3,544)	(5,219)	2,215	(55)
Total income tax expense (benefit)	19,201	13,917	35,474	30,855
Earnings before equity in earnings of nonconsolidated subsidiaries	43,442	29,439	77,613	60,946
Equity in earnings of nonconsolidated subsidiaries	0	0	0	0
Net earnings	43,442	29,439	77,613	60,946
Less: Earnings attributable to noncontrolling interests	(1,416)	(1,566)	(2,618)	(2,334)
Net earnings attributable to Valmont Industries, Inc.	$ 42,026	$ 27,873	$ 74,995	$ 58,612
Earnings per share:
Basic (in dollars per share)	$ 1.86	$ 1.19	$ 3.31	$ 2.48
Diluted (in dollars per share)	1.85	1.19	3.29	2.47
Cash dividends declared per share (in dollars per share)	$ 0.375	$ 0.375	$ 0.75	$ 0.75
Weighted average number of shares of common stock outstanding - Basic (in shares)	22,602	23,336	22,651	23,602
Weighted average number of shares of common stock outstanding - Diluted (in shares)	22,749	23,450	22,782	23,716