CONSOLIDATED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Revenues	$ 30,689	$ 31,139	$ 59,929	$ 61,728
Cost of goods sold	16,016	14,684	31,427	29,721
Gross profit	14,673	16,455	28,502	32,007
Operating expenses:
Selling	1,465	1,341	2,907	2,836
General and administrative	3,397	3,949	6,868	7,333
Research and development	844	728	1,817	1,305
Operating Expenses, Total	5,706	6,018	11,592	11,474
Operating income	8,967	10,437	16,910	20,533
Interest income	359	342	649	668
Other income			2	2
Nonoperating Income (Expense), Total	359	342	651	670
Income before provision for income taxes	9,326	10,779	17,561	21,203
Provision for income taxes	(3,227)	(3,760)	(6,085)	(7,326)
Net Income	6,099	7,019	11,476	13,877
Other comprehensive income, net of tax: None
Comprehensive income	$ 6,099	$ 7,019	$ 11,476	$ 13,877
Income per basic share	$ 3.03	$ 3.48	$ 5.70	$ 6.88
Weighted average basic shares outstanding	2,016	2,019	2,015	2,018
Income per diluted share	$ 3.02	$ 3.46	$ 5.67	$ 6.84
Weighted average diluted shares outstanding	2,019	2,030	2,023	2,030
Dividends per common share	$ 0.49	$ 0.42	$ 0.98	$ 0.84