Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 144,737	$ 114,781
Accounts receivable, net of allowance for doubtful accounts of $115 and $58 at December 31, 2012 and 2011, respectively	41,999	34,433
Inventories	20,693	18,637
Prepaid expenses	3,048	2,793
Prepaid income taxes	326	4,142
Deferred income taxes	593	556
Other current assets	513	398
Total current assets	211,909	175,740
Property, plant and equipment, net	52,725	44,282
Goodwill	28,515	28,515
Intangible assets with finite lives, net	18,858	22,706
Other assets	538	474
Total assets	312,545	271,717
Current liabilities:
Trade accounts payable	14,276	11,526
Accrued expenses	11,820	8,435
Accrued compensation and other benefits	4,138	4,328
Dividends payable	0	5,237
Current portion of long-term debt	0	1,387
Total current liabilities	30,234	30,913
Long-term debt	0	23
Deferred income taxes	5,868	5,984
Other long-term obligations	3,431	2,788
Total liabilities	39,533	39,708
Commitments and contingencies (note 11)
Stockholders' equity:
Preferred stock, $25 par value. Authorized 2,000,000 shares; none issued and outstanding	0	0
Common stock, $.0667 par value. Authorized 60,000,000 shares; 29,454,171 shares issued and outstanding at December 31, 2012 and 29,165,721 shares issued and outstanding at December 31, 2011	1,964	1,944
Additional paid-in capital	57,198	49,933
Retained earnings	214,609	181,070
Accumulated other comprehensive loss	(759)	(938)
Total stockholders' equity	273,012	232,009
Total liabilities and stockholders' equity	$ 312,545	$ 271,717