Condensed Consolidated Balance Sheets (unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 207,330	$ 208,747
Accounts receivable, net of allowance for doubtful accounts of $115 at March 31, 2014 and December 31, 2013	43,812	39,386
Inventories	24,860	24,824
Prepaid expenses	2,127	2,580
Prepaid income taxes	0	899
Deferred income taxes	887	893
Other current assets	5,866	445
Total current assets	284,882	277,774
Property, plant and equipment, net	54,394	54,916
Goodwill	28,515	28,515
Intangible assets with finite lives, net	14,158	15,126
Other assets	501	541
Total assets	382,450	376,872
Current liabilities:
Trade accounts payable	13,236	12,395
Accrued expenses	12,605	10,732
Accrued compensation and other benefits	2,273	4,770
Dividends payable	0	7,856
Income taxes payable	225	0
Total current liabilities	28,339	35,753
Deferred income taxes	5,931	5,884
Other long-term obligations	3,977	3,877
Total liabilities	38,247	45,514
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; 30,368,219 shares issued and outstanding at March 31, 2014 and 30,225,763 shares issued and outstanding at December 31, 2013	2,025	2,016
Additional paid-in capital	81,479	77,517
Retained earnings	260,521	251,627
Accumulated other comprehensive income	178	198
Total stockholders' equity	344,203	331,358
Total liabilities and stockholders' equity	$ 382,450	$ 376,872