Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
Net Sales	$ 117,115	$ 110,996	$ 228,600	$ 203,172
Costs, expenses and other income:
Cost of goods sold	83,744	81,516	163,699	153,191
Selling and administrative	10,163	9,363	19,123	17,791
Long Term Incentive Plan funded by Lone Star	0	15,842	0	20,013
Total costs and operating expenses	93,907	106,721	182,822	190,995
Operating income	23,208	4,275	45,778	12,177
Other income/(expense), net	6	31	160	(417)
Interest expense, net	(3,648)	(4,184)	(7,346)	(8,405)
Income before losses from equity method investment and (provision for)/benefit from income tax	19,566	122	38,592	3,355
Losses from equity method investment	(240)	(311)	(435)	(252)
Income/(loss) before (provision for)/benefit from income taxes	19,326	(189)	38,157	3,103
(Provision for)/benefit from income taxes	(6,604)	63	(12,934)	(1,209)
Net income/(loss)	$ 12,722	$ (126)	$ 25,223	$ 1,894
Net income per share:
Basic (usd per share)	$ 0.31	$ 0.00	$ 0.61	$ 0.04
Diluted (usd per share)	$ 0.31	$ 0.00	$ 0.61	$ 0.04
Weighted average shares outstanding:
Basic (shares)	40,670,650	43,606,410	41,097,472	43,840,105
Diluted (shares)	40,717,162	43,606,410	41,128,466	43,876,757