GUARANTOR/NON-GUARANTOR FINANCIAL INFORMATION (Details 2) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2015	Jun. 28, 2014	Jun. 27, 2015	Jun. 28, 2014
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	$ 29,439	$ 65,852	$ 60,946	$ 122,415
Foreign currency translation adjustments:
Unrealized translation gain (loss)	18,328	13,869	(39,850)	25,506
Unrealized gain/(loss) on cash flow hedge:
Amortization cost included in interest expense	19	(33)	37	67
Gain on cash flow hedges	751		1,045
Actuarial gain (loss) in defined benefit pension plan liability		(614)		(847)
Other comprehensive income (loss)	19,098	13,222	(38,768)	24,726
Comprehensive income (loss)	48,537	79,074	22,178	147,141
Comprehensive loss (income) attributable to noncontrolling interests	(1,968)	(1,792)	(641)	(1,704)
Comprehensive income (loss) attributable to Valmont Industries, Inc.	46,569	77,282	21,537	145,437
Parent
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	27,873	63,976	58,612	119,956
Unrealized gain/(loss) on cash flow hedge:
Amortization cost included in interest expense	19	100	37	200
Gain on cash flow hedges	(301)		(209)
Equity in other comprehensive income	18,978	13,206	(36,903)	25,281
Other comprehensive income (loss)	18,696	13,306	(37,075)	25,481
Comprehensive income (loss)	46,569	77,282	21,537	145,437
Comprehensive income (loss) attributable to Valmont Industries, Inc.	46,569	77,282	21,537	145,437
Guarantors
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	8,580	21,402	18,524	37,086
Foreign currency translation adjustments:
Unrealized translation gain (loss)	76	(126)	(8,812)	1,063
Unrealized gain/(loss) on cash flow hedge:
Other comprehensive income (loss)	76	(126)	(8,812)	1,063
Comprehensive income (loss)	8,656	21,276	9,712	38,149
Comprehensive income (loss) attributable to Valmont Industries, Inc.	8,656	21,276	9,712	38,149
Non-Guarantors
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	11,784	27,420	24,834	37,107
Foreign currency translation adjustments:
Unrealized translation gain (loss)	18,252	13,995	(31,038)	24,443
Unrealized gain/(loss) on cash flow hedge:
Amortization cost included in interest expense		(133)		(133)
Gain on cash flow hedges	1,052		1,254
Actuarial gain (loss) in defined benefit pension plan liability		(614)		(847)
Other comprehensive income (loss)	19,304	13,248	(29,784)	23,463
Comprehensive income (loss)	31,088	40,668	(4,950)	60,570
Comprehensive loss (income) attributable to noncontrolling interests	(1,968)	(1,792)	(641)	(1,704)
Comprehensive income (loss) attributable to Valmont Industries, Inc.	29,120	38,876	(5,591)	58,866
Eliminations
Condensed consolidated financial information for the Company (Parent), the guarantor subsidiaries and the non-guarantor subsidiaries
Net earnings	(18,798)	(46,946)	(41,024)	(71,734)
Unrealized gain/(loss) on cash flow hedge:
Equity in other comprehensive income	(18,978)	(13,206)	36,903	(25,281)
Other comprehensive income (loss)	(18,978)	(13,206)	36,903	(25,281)
Comprehensive income (loss)	(37,776)	(60,152)	(4,121)	(97,015)
Comprehensive income (loss) attributable to Valmont Industries, Inc.	$ (37,776)	$ (60,152)	$ (4,121)	$ (97,015)