Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 5,915	$ 37,978
Receivables, less allowance for doubtful accounts of $761 at June 30, 2018 and $652 at December 31, 2017	30,179	21,381
Inventories	18,732	12,863
Prepaid expenses	2,106	1,835
Refundable income taxes	616	1,017
Total current assets	57,548	75,074
Property, plant and equipment	111,289	106,716
Less accumulated depreciation and amortization	(52,600)	(53,064)
Net property, plant and equipment	58,689	53,652
Goodwill	51,838	7,322
Intangible assets, net	22,860
Non-qualified deferred compensation plan	2,216	2,015
Other assets	191	144
Total assets	193,342	138,207
Current liabilities:
Accounts payable	8,743	4,180
Accrued expenses	5,407	5,466
Deferred revenue	3,331	297
Current portion of long-term debt	2,857
Total current liabilities	20,338	9,943
Long-term debt, excluding current portion	36,714
Deferred income taxes	2,937	2,440
Non-qualified deferred compensation plan	2,215	2,030
Other liabilities	52	82
Total liabilities	62,256	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; 7,389,116 and 7,359,557 shares issued and outstanding, respectively at June 30, 2018; 7,309,909 and 7,280,350 shares issued and outstanding, respectively at December 31, 2017	73	73
Additional paid-in capital	28,341	26,664
Retained earnings	103,259	97,562
Treasury stock at cost, 29,559 shares at June 30, 2018 and December 31, 2017	(587)	(587)
Total stockholders’ equity	131,086	123,712
Total liabilities and stockholders' equity	$ 193,342	$ 138,207