Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities
Net income	$ 40,518	$ 123,385	$ 26,762
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation, amortization and accretion	13,929	19,231	18,263
Amortization of debt related costs	1,279	1,361	1,603
Provision for bad debt	321	136	53
Provision for excess and obsolete inventory	2,875	1,215	1,342
Stock-based compensation	8,718	5,928	2,524
Gain on sales of assets	0	0	(6,385)
Loss on impairment of land	0	912	0
Loss on extinguishment of debt and debt retirement costs	0	2,442	1,896
Deferred taxes	5,762	(86,946)	(155)
Long-term income tax receivable	(2,855)	(8,413)	(200)
Long-term income tax payable and other long-term liabilities	3,219	2,793	565
Other	1,399	1,049	1,284
Increases (decreases) in cash from operating assets and liabilities:
Accounts receivable	(3,985)	(3,407)	(1,059)
Inventory	(8,690)	(9,620)	(3,626)
Other current assets	(661)	(388)	(155)
Accounts payable	(2,886)	604	5,700
Accrued expenses and other liabilities	2,250	4,495	1,230
Net cash provided by operating activities	61,193	54,777	49,642
Investing activities
Capital expenditures	(20,132)	(17,543)	(7,398)
Proceeds from sale of assets	1,000	1,234	10,605
Other	0	0	74
Net cash (used in) provided by investing activities	(19,132)	(16,309)	3,281
Financing activities
Proceeds from issuance of common stock	428	187	50,900
Payments for public offering costs	0	(74)	(2,006)
Proceeds from issuance of long-term debt	0	274,313	0
Payments on long-term debt	(2,862)	(286,694)	(78,729)
Deferred financing costs	0	(1,576)	(11)
Proceeds from stock option exercises	1,152	3,247	231
Payments for minimum statutory tax withholding related to net share settlement of equity awards	(3,386)	(2,853)	(602)
Net cash used in financing activities	(4,668)	(13,450)	(30,217)
Effect of foreign exchange rates on cash and cash equivalents	(282)	94	(124)
Net increase in cash and cash equivalents	37,111	25,112	22,582
Cash and cash equivalents, beginning of year	76,290	51,178	28,596
Cash and cash equivalents, end of year	113,401	76,290	51,178
Supplemental disclosure of cash flow information
Interest	15,869	16,653	24,441
Income taxes, net of refunds of $35, $17 and $82, respectively	90	106	265
Schedule of non-cash investing and financing activities
Additions of property, plant and equipment included in liabilities	7,395	2,738	4,990
Receivable in connection with sale of Australian subsidiary	$ 0	$ 0	$ 1,479