Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 30,724	$ 7,999
Short-term investments	8,448	8,182
Accounts receivable	16,183	13,054
Inventories	26,488	23,779
Prepaid expenses and other current assets	1,592	3,110
Deferred income taxes	623	623
Total Current Assets	84,058	56,747
Long-term investments	20,104	28,433
Property, plant and equipment	127,851	124,180
Less accumulated depreciation and amortization	70,163	64,912
Property plant and equipment net	57,688	59,268
Other assets and deferred charges:
Patents	716	837
Goodwill	9,730	9,730
Other	812	795
Prepaid Expense and Other Assets, Noncurrent, Total	11,258	11,362
Total assets	173,108	155,810
Current liabilities:
Accounts payable and accrued liabilities	9,268	6,743
Accrued income and other taxes	1,636	465
Total Current Liabilities	10,904	7,208
Line of credit
Other non-current liabilities	12,968	13,774
Stockholders' equity:
Common stock, par value $0.10 per share; authorized 10,000 shares, issued 3,420 shares	342	342
Paid-in capital	31,203	29,998
Retained earnings	169,883	152,630
Treasury shares,1,417 at September 30, 2013 and 1,399 at December 31, 2012, at cost	(52,192)	(48,142)
Total stockholders' equity	149,236	134,828
Total liabilities and stockholders' equity	$ 173,108	$ 155,810