BUSINESS SEGMENTS (Tables)

9 Months Ended

Sep. 30, 2017

Segment Reporting [Abstract]

Segment reporting information of sales and operating income

(7) BUSINESS SEGMENTS (Continued)

Summary by Business

	Thirteen Weeks Ended						Thirty-nine Weeks Ended
	September 30, 2017			September 24, 2016			September 30, 2017			September 24, 2016
SALES:
Engineered Support Structures segment:
Lighting, Traffic, and Roadway Products	$	175,184		$	159,089		$	498,034		$	468,582
Communication Products	46,324			44,095			121,613			115,489
Engineered Support Structures segment	221,508			203,184			619,647			584,071
Energy and Mining segment:
Offshore and Other Complex Steel Structures	25,046			27,330			75,372			76,207
Grinding Media	19,800			20,681			60,466			61,189
Access Systems	34,909			33,541			99,096			97,297
Energy and Mining segment	79,755			81,552			234,934			234,693
Utility Support Structures segment:
Steel	160,948			131,085			471,072			379,157
Concrete	18,811			19,582			67,921			67,275
Utility Support Structures segment	179,759			150,667			538,993			446,432
Coatings segment	82,593			70,082			235,842			213,961
Irrigation segment	147,428			127,809			502,939			438,575
Total	711,043			633,294			2,132,355			1,917,732
INTERSEGMENT SALES:
Engineered Support Structures segment	11,736			10,076			48,399			29,202
Energy & Mining segment	6			319			6			3,386
Utility Support Structures segment	1,231			276			2,448			538
Coatings segment	14,913			10,079			44,230			31,778
Irrigation segment	2,378			2,297			6,283			5,727
Total	30,264			23,047			101,366			70,631
NET SALES:
Engineered Support Structures segment	209,772			193,108			571,248			554,869
Energy & Mining segment	79,749			81,233			234,928			231,307
Utility Support Structures segment	178,528			150,391			536,545			445,894
Coatings segment	67,680			60,003			191,612			182,183
Irrigation segment	145,050			125,512			496,656			432,848
Total	$	680,779		$	610,247		$	2,030,989		$	1,847,101
OPERATING INCOME:
Engineered Support Structures segment	$	16,226		$	20,323		$	45,683		$	53,615
Energy & Mining segment	1,417			3,941			9,195			9,184
Utility Support Structures segment	22,108			16,195			65,005			48,201
Coatings segment	14,577			11,696			36,091			37,132
Irrigation segment	18,235			15,308			83,196			75,216
Adjustment to LIFO inventory valuation method	(1,626		)	(2,066		)	(2,839		)	(3,192		)
Corporate	(11,014		)	(12,157		)	(33,616		)	(32,745		)
Total	$	59,923		$	53,240		$	202,715		$	187,411