Condensed Consolidated Balance Sheets (Unaudited) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 104,584,000	$ 76,290,000
Accounts receivable, net	47,135,000	40,259,000
Inventory	34,572,000	26,080,000
Other current assets	4,669,000	5,221,000
Total current assets	190,960,000	147,850,000
Property, plant & equipment, net	99,407,000	92,999,000
Intangibles, net	9,727,000	11,798,000
Goodwill	15,714,000	15,714,000
Deferred tax assets, net	79,358,000	87,010,000
Other long-term assets	29,652,000	28,487,000
Total assets	424,818,000	383,858,000
Current liabilities
Current portion of long-term debt	2,750,000	2,750,000
Revolving line of credit	0	0
Accounts payable	20,363,000	17,464,000
Accrued expenses and other liabilities	31,464,000	26,536,000
Total current liabilities	54,577,000	46,750,000
Asset retirement obligations	11,282,000	10,412,000
Long-term debt, net	264,130,000	265,393,000
Other long-term liabilities	39,321,000	38,012,000
Total liabilities	369,310,000	360,567,000
Commitments and contingencies (See Note 13)
Stockholders’ equity
Preferred stock ($0.01 par value, 25,000 shares authorized; no shares issued and outstanding)	0	0
Common stock ($0.01 par value, 250,000 shares authorized; 38,463 and 37,765 shares issued and outstanding, respectively)	385,000	378,000
Additional paid-in capital	237,587,000	232,960,000
Accumulated deficit	(181,432,000)	(209,013,000)
Accumulated other comprehensive loss	(1,032,000)	(1,034,000)
Total stockholders’ equity	55,508,000	23,291,000
Total liabilities and stockholders’ equity	$ 424,818,000	$ 383,858,000