Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 5,088	$ 37,978
Receivables, less allowance for doubtful accounts of $786 at September 30, 2018 and $652 at December 31, 2017	30,144	21,381
Inventories	19,902	12,863
Prepaid expenses	2,219	1,835
Refundable income taxes	966	1,017
Total current assets	58,319	75,074
Property, plant and equipment	112,503	106,716
Less accumulated depreciation and amortization	(54,044)	(53,064)
Net property, plant and equipment	58,459	53,652
Goodwill	51,838	7,322
Intangible assets, net	22,546
Non-qualified deferred compensation plan	2,323	2,015
Other assets	275	144
Total assets	193,760	138,207
Current liabilities:
Accounts payable	7,970	4,180
Accrued expenses	6,569	5,466
Deferred revenue	3,918	297
Current portion of long-term debt	2,857
Total current liabilities	21,314	9,943
Long-term debt, excluding current portion	31,000
Deferred income taxes	3,256	2,440
Non-qualified deferred compensation plan	2,328	2,030
Other liabilities	65	82
Total liabilities	57,963	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; 7,402,766 and 7,373,207 shares issued and outstanding, respectively at September 30, 2018; 7,309,909 and 7,280,350 shares issued and outstanding, respectively at December 31, 2017	74	73
Additional paid-in capital	28,918	26,664
Retained earnings	107,392	97,562
Treasury stock at cost, 29,559 shares at both September 30, 2018 and December 31, 2017	(587)	(587)
Total stockholders’ equity	135,797	123,712
Total liabilities and stockholders' equity	$ 193,760	$ 138,207

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).