Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 26,921	$ 28,559
Short-term investments	18,178	18,351
Accounts receivable	18,399	14,164
Inventories	28,408	26,266
Prepaid expenses and other current assets	1,974	1,603
Deferred income taxes	1,376	1,376
Total Current Assets	95,256	90,319
Long-term investments	10,000	10,069
Property, plant and equipment	138,426	130,504
Less accumulated depreciation and amortization	77,980	72,176
Property plant and equipment net	60,446	58,328
Other assets and deferred charges:
Patents	2,606	2,808
Goodwill	9,730	9,730
Other	882	812
Prepaid Expense and Other Assets, Noncurrent, Total	13,218	13,350
Total assets	178,920	172,066
Current liabilities:
Accounts payable and accrued liabilities	9,891	8,511
Accrued income and other taxes	890	853
Total Current Liabilities	10,781	9,364
Line of credit	0	0
Other non-current liabilities	11,797	13,708
Stockholders' equity:
Common stock, par value $0.10 per share; authorized 10,000 shares, issued 3,420 shares	342	342
Paid-in capital	33,554	31,592
Retained earnings	192,129	174,362
Treasury shares,1,473 at September 30, 2014 and 1,435 at December 31, 2013, at cost	(69,683)	(57,302)
Total stockholders' equity	156,342	148,994
Total liabilities and stockholders' equity	$ 178,920	$ 172,066