Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Assets
Cash and cash equivalents	$ 43,096	$ 86,050
Marketable securities, current portion	99,738	70,397
Accounts receivable, net of allowances of $881 and $881, respectively	63,427	60,806
Inventories, net	91,046	87,555
Deferred income taxes	2,347	4,488
Prepaid expenses	16,480	12,199
Other current assets	16,143	9,049
Total current assets	332,277	330,544
Property, plant, and equipment, net	125,956	125,099
Goodwill	46,425	46,830
Other intangibles, net	45,059	46,930
Marketable securities, non-current	8,240	12,073
Deferred income taxes, non-current	15,003	15,065
Other non-current assets	22,116	22,612
Total assets	595,076	599,153
Liabilities and stockholders' equity
Accounts payable	35,541	38,573
Accrued liabilities	8,275	7,997
Accrued salaries and related benefits	7,339	5,992
Income taxes payable	13,054	16,256
Other current liabilities	5,600	6,084
Total current liabilities	69,809	74,902
Deferred income taxes, non-current	179	165
Other non-current liabilities	15,581	16,810
Commitments and contingencies (Note 7)
Stockholders' equity:
Preferred stock, par value $.01 per share: 2,000 shares authorized; none issued
Common stock, par value $.01 per share: 100,000 shares authorized; 40,745 and 40,476 issued and 31,930 and 31,983 outstanding in 2013 and 2012, respectively	407	405
Additional paid-in capital	460,496	457,669
Treasury stock at cost (8,815 and 8,493 shares in 2013 and 2012, respectively)	(244,316)	(237,170)
Retained earnings	279,170	270,744
Accumulated other comprehensive income	13,750	15,628
Total stockholders' equity	509,507	507,276
Total liabilities and stockholders' equity	$ 595,076	$ 599,153