Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Activities:
Net income (loss)	$ 10,662	$ 7,610	$ (5,347)
Adjustments for non-cash items:
Depreciation and amortization	18,918	18,823	18,533
Deferred income tax	1,850	(7,593)	(3,525)
Write-off of deferred financing costs			768
Share-based compensation expense	1,442	1,564	1,405
Net gain on asset disposals	(9)	(70)	(340)
Changes in assets and liabilities:
Accounts receivable, net	(7,628)	(5,567)	(1,754)
Inventory, net	(20,373)	(27,378)	(9,155)
Accounts payable	5,293	14,178	7,096
Accrued employment costs	3,865	272	547
Income taxes	(246)	77	200
Other, net	2,833	(811)	(22)
Net cash provided by operating activities	16,607	1,105	8,406
Investing Activities:
Capital expenditures	(15,388)	(7,996)	(4,376)
Proceeds from sale of property, plant and equipment	10	70	1,571
Net cash used in investing activities	(15,378)	(7,926)	(2,805)
Financing Activities:
Borrowings under revolving credit facility	368,910	350,314	241,152
Payments on revolving credit facility	(388,728)	(338,836)	(259,243)
Proceeds under New Markets Tax Credit financing, net	2,835
Borrowings under term loan facility			30,000
Payments on term loan facility, capital leases, and notes	(12,364)	(5,078)	(17,448)
Payments of financing costs	(1,109)		(750)
Proceeds from public offering, net of cash expenses	32,246
Proceeds from the exercise of stock options	865	553	651
Net cash provided by (used in) financing activities	2,655	6,953	(5,638)
Net increase (decrease) in cash and restricted cash	3,884	132	(37)
Cash and restricted cash at beginning of period	207	75	112
Cash and restricted cash at end of period	4,091	207	75
Supplemental Disclosure of Cash Flow Information:
Interest paid	4,183	4,027	3,451
Income taxes paid (refunded), net	$ 102	$ (85)	$ (201)