CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
NET SALES	$ 1,845,444	$ 2,027,489	$ 1,863,315
COST OF SALES	1,519,910	1,724,046	1,630,681
Gross profit	325,534	303,443	232,634
GENERAL AND ADMINISTRATIVE EXPENSES	74,129	73,495	61,694
SELLING EXPENSES	27,270	27,233	26,676
AMORTIZATION OF INTANGIBLES	19,940	21,259	21,878
OTHER OPERATING EXPENSES	1,663	1,087	0
Income from operations	202,532	180,369	122,386
OTHER INCOME (EXPENSE):
Interest expense	(15,663)	(19,548)	(22,165)
Other, net	(1,452)	2,490	(1,759)
Income before income taxes	185,417	163,311	98,462
INCOME TAX EXPENSE	65,984	59,022	37,532
Net income	$ 119,433	$ 104,289	$ 60,930
BASIC NET INCOME PER SHARE	$ 1.87	$ 1.55	$ 0.88
DILUTED NET INCOME PER SHARE	$ 1.82	$ 1.50	$ 0.85