Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 19,670	$ 12,085
Certificates of deposit	9,105	8,110
Investments held to maturity at amortized cost	22,808	16,040
Accounts receivable, net	45,704	39,063
Income tax receivable	0	1,073
Notes receivable	29	29
Inventories, net	34,891	32,140
Prepaid expenses and other	701	304
Deferred tax assets	5,488	4,779
Total current assets	138,396	113,623
Property, plant and equipment:
Land	2,233	1,417
Buildings	62,744	61,821
Machinery and equipment	120,942	119,439
Furniture and fixtures	9,934	9,748
Total property, plant and equipment	195,853	192,425
Less: Accumulated depreciation	107,678	105,142
Property, plant and equipment, net	88,175	87,283
Certificates of deposit	240	2,638
Investments held to maturity at amortized cost	1,027	10,981
Note receivable	881	919
Total assets	228,719	215,444
Current liabilities:
Revolving credit facility	0	0
Accounts payable	11,307	7,779
Accrued liabilities	30,643	28,550
Total current liabilities	41,950	36,329
Deferred revenue	735	585
Deferred tax liabilities	13,979	14,424
Commitments and contingencies
Stockholders' equity:
Preferred stock, $.001 par value, 5,000,000 shares authorized, no shares issued	0	0
Common stock, $.004 par value, 50,000,000 shares authorized, 36,652,276 and 36,711,354 issued and outstanding at March 31, 2014 and December 31, 2013, respectively	147	147
Additional paid-in capital	0	0
Retained earnings	171,908	163,959
Total stockholders' equity	172,055	164,106
Total liabilities and stockholders' equity	$ 228,719	$ 215,444