Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 25, 2017	Jun. 30, 2018	Jun. 25, 2017
Income Statement [Abstract]
NET SALES	$ 388,944	$ 240,628	$ 775,392	$ 414,848
Cost of sales	335,385	220,601	671,842	375,409
Restructuring costs		(78)		130
Cost of sales, including restructuring costs	335,385	220,523	671,842	375,539
GROSS PROFIT	53,559	20,105	103,550	39,309
Selling, general and administrative expenses	22,289	22,103	44,646	37,363
INCOME (LOSS) FROM OPERATIONS	31,270	(1,998)	58,904	1,946
Interest expense, net	(13,182)	(14,729)	(25,039)	(15,025)
Other (expense) income, net	(570)	7,486	(3,558)	7,138
Change in fair value of redeemable preferred stock embedded derivative	(4,588)		(3,690)
CONSOLIDATED INCOME (LOSS) BEFORE INCOME TAXES	12,930	(9,241)	26,617	(5,941)
Income tax (provision) benefit	(4,795)	1,722	(8,165)	1,524
CONSOLIDATED NET INCOME (LOSS)	8,135	(7,519)	18,452	(4,417)
Less: Net loss attributable to non-controlling interest		247		247
NET INCOME (LOSS) ATTRIBUTABLE TO SUPERIOR	$ 8,135	$ (7,272)	$ 18,452	$ (4,170)
EARNINGS (LOSS) PER SHARE ATTRIBUTABLE TO SUPERIOR- BASIC	$ 0.09	$ (0.41)	$ 0.16	$ (0.28)
EARNINGS (LOSS) PER SHARE ATTRIBUTABLE TO SUPERIOR- DILUTED	0.09	(0.41)	0.16	(0.28)
DIVIDENDS DECLARED PER SHARE	$ 0.09	$ 0.09	$ 0.18	$ 0.27