Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 7,064	$ 37,978
Receivables, less allowance for doubtful accounts of $730 at March 31, 2018 and $652 at December 31, 2017	29,285	21,381
Inventories	18,258	12,863
Prepaid expenses	2,716	1,835
Refundable income taxes	776	1,017
Total current assets	58,099	75,074
Property, plant and equipment	113,935	106,716
Less accumulated depreciation and amortization	(55,148)	(53,064)
Net property, plant and equipment	58,787	53,652
Goodwill	51,838	7,322
Intangible assets, net	23,186
Non-qualified deferred compensation plan	2,126	2,015
Other assets	188	144
Total assets	194,224	138,207
Current liabilities:
Accounts payable	5,412	4,180
Accrued expenses	5,540	5,466
Deferred revenue	3,130	297
Current portion of long-term debt	2,857
Total current liabilities	16,939	9,943
Long-term debt, excluding current portion	46,429
Deferred income taxes	2,620	2,440
Non-qualified deferred compensation plan	2,148	2,030
Other liabilities	67	82
Total liabilities	68,203	14,495
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $.01 par value, 1,000,000 shares authorized; zero shares issued or outstanding
Common stock, $.01 par value, 20,000,000 shares authorized; 7,351,172 and 7,321,613 shares issued and outstanding, respectively at March 31, 2018; 7,309,909 and 7,280,350 shares issued and outstanding, respectively at December 31, 2017	73	73
Additional paid-in capital	27,291	26,664
Retained earnings	99,244	97,562
Treasury stock at cost, 29,559 shares at March 31, 2018 and 29,559 at December 31, 2017	(587)	(587)
Total stockholders’ equity	126,021	123,712
Total liabilities and stockholders' equity	$ 194,224	$ 138,207