Condensed Consolidated Balance Sheets (unaudited) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 171,220	$ 144,737
Accounts receivable, net	39,679	41,999
Inventories	24,714	20,693
Prepaid expenses	1,954	3,048
Prepaid income taxes	0	326
Deferred income taxes	801	593
Other current assets	433	513
Total current assets	238,801	211,909
Property, plant and equipment, net	54,512	52,725
Goodwill	28,515	28,515
Intangible assets with finite lives, net	17,084	18,858
Other assets	538	538
Total assets	339,450	312,545
Current liabilities:
Trade accounts payable	10,315	14,276
Accrued expenses	11,460	11,820
Accrued compensation and other benefits	3,234	4,138
Income taxes payable	460	0
Total current liabilities	25,469	30,234
Deferred income taxes	5,282	5,868
Other long-term obligations	3,307	3,431
Total liabilities	34,058	39,533
Commitments and contingencies (note 12)
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; 29,852,278 shares issued and outstanding at June 30, 2013 and 29,454,171 shares issued and outstanding at December 31, 2012	1,990	1,964
Additional paid-in capital	67,349	57,198
Retained earnings	237,079	214,609
Accumulated other comprehensive loss	(1,026)	(759)
Total stockholders' equity	305,392	273,012
Total liabilities and stockholders' equity	$ 339,450	$ 312,545