CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 8,395	$ 24,590
Short-term investments	17,377	20,279
Accounts receivable	14,921	11,223
Inventories	24,899	24,582
Prepaid expenses	2,218	2,313
Deferred income taxes	755	755
Assets, Current, Total	68,565	83,742
Long-term investments	27,665	10,336
Property, plant and equipment	120,127	114,975
Less accumulated depreciation and amortization	61,658	58,605
Property, Plant and Equipment, Net, Total	58,469	56,370
Other assets and deferred charges:
Patents	918	999
Goodwill	9,730	9,730
Other	799	718
Prepaid Expense and Other Assets, Noncurrent, Total	11,447	11,447
Assets, Total	166,146	161,895
Current liabilities:
Accounts payable and accrued liabilities	8,010	9,208
Accrued income and other taxes	466	835
Liabilities, Current, Total	8,476	10,043
Line of credit
Other non-current liabilities	13,666	13,338
Stockholders' equity:
Common shares, par value $0.10 per share; authorized 10,000 shares, issued 3,420 shares	342	342
Paid-in capital	28,146	25,452
Retained earnings	163,104	153,618
Treasury shares,1,406 at June 30, 2012 and 1,404 at December 31, 2011, at cost	(47,588)	(40,898)
Total stockholders' equity	144,004	138,514
Liabilities and Equity, Total	$ 166,146	$ 161,895