CONSOLIDATED BALANCE SHEET - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current Assets:
Cash and cash equivalents	$ 30,136	$ 20,022
Short-term investments	35,468	24,080
Accounts receivable, net of allowance for doubtful accounts of $28 and $71 in 2017 and 2016, respectively	17,076	17,166
Inventories	29,354	29,015
Prepaid expenses and other current assets	3,199	3,181
Total Current Assets	115,233	93,464
Long-term investments	9,136	9,945
Property, Plant and Equipment	167,080	160,413
Less accumulated depreciation and amortization	100,711	95,148
Property, Plant and Equipment, net	66,369	65,265
Other Assets and Deferred Charges:
Patents and licenses, net of accumulated amortization of $12,062 and $11,911 in 2017 and 2016, respectively	1,778	1,929
Goodwill	9,730	9,730
Other	1,534	1,609
Prepaid Expense and Other Assets, Noncurrent, Total	13,042	13,268
Total Assets	203,780	181,942
Current Liabilities:
Accounts payable	3,929	4,028
Accrued liabilities	4,947	4,635
Accrued income and other taxes	746	410
Total Current Liabilities	9,622	9,073
Line of credit	0	0
Other Liabilities and Deferred Credits:
Deferred income taxes	7,312	8,753
Other	2,458	1,128
Liabilities Noncurrent	9,770	9,881
Total Liabilities	19,392	18,954
Stockholders' Equity:
Common stock, par value $.10 per share, authorized 10,000 shares, issued 3,420 shares	342	342
Additional paid-in capital	48,730	37,448
Accumulated other comprehensive loss	(1,215)	(474)
Retained earnings	268,194	239,946
Treasury shares, 1,584 shares in 2017 and 1,596 shares in 2016, at cost	(131,663)	(114,274)
Total Stockholders' Equity	184,388	162,988
Total Liabilities and Stockholders' Equity	$ 203,780	$ 181,942