CONDENSED CONSOLIDATED STATEMENTS OF EARNINGS - USD ($) shares in Thousands	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Sales	$ 2,757,144,000	$ 2,745,967,000	$ 2,521,676,000
Cost of sales	2,098,864,000	2,064,199,000	1,865,433,000
Gross profit	658,280,000	681,768,000	656,243,000
Selling, general and administrative expenses	440,220,000	414,688,000	410,869,000
Impairment of goodwill and intangible assets	15,780,000	0	0
Operating income	202,280,000	267,080,000	245,374,000
Other income (expenses):
Interest expense	(44,237,000)	(44,645,000)	(44,409,000)
Interest income	4,668,000	4,737,000	3,105,000
Costs associated with refinancing of debt	(14,820,000)	0	0
Loss on divestiture of grinding media business	(6,084,000)	0	0
Other Nonoperating Income (Expense) excluding Sale of Business and Debt Costs	1,634,000	1,292,000	16,384,000
Total other income (expenses)	(58,839,000)	(38,616,000)	(24,920,000)
Earnings before income taxes and equity in earnings of nonconsolidated subsidiaries	143,441,000	228,464,000	220,454,000
Income tax expense (benefit):
Current	44,794,000	66,390,000	65,748,000
Deferred	(1,659,000)	39,755,000	(23,685,000)
Total income tax expense (benefit)	43,135,000	106,145,000	42,063,000
Comprehensive income	78,772,000	189,106,000	100,235,000
Earnings before equity in earnings of nonconsolidated subsidiaries	100,306,000	122,319,000	178,391,000
Equity in earnings of nonconsolidated subsidiaries	0	0	0
Net earnings	100,306,000	122,319,000	178,391,000
Less: Earnings attributable to noncontrolling interests	(5,955,000)	(6,079,000)	(5,159,000)
Net earnings attributable to Valmont Industries, Inc.	$ 94,351,000	$ 116,240,000	$ 173,232,000
Earnings per share:
Basic (in dollars per share)	$ 4.23	$ 5.16	$ 7.68
Diluted (in dollars per share)	4.20	5.11	$ 7.63
Cash dividends declared per share (in dollars per share)	$ 1.500	$ 1.500
Weighted average number of shares of common stock outstanding - Basic (in shares)	22,306	22,520	22,562
Weighted average number of shares of common stock outstanding - Diluted (in shares)	22,446	22,738	22,709
Product
Sales	$ 2,437,334,000	$ 2,447,219,000	$ 2,255,860,000
Cost of sales	1,887,959,000	1,860,087,000	1,682,355,000
Service
Sales	319,810,000	298,748,000	265,816,000
Cost of sales	$ 210,905,000	$ 204,112,000	$ 183,078,000