Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 7,908	$ 21,952
Certificates of deposit	10,080	6,098
Held-to-maturity Securities, Current	12,444	11,972
Accounts receivable, net	50,024	44,092
Income tax receivable	4,702	2,569
Note receivable	23	30
Inventories, net	38,499	37,618
Prepaid expenses and other	533	609
Total current assets	124,213	124,940
Property, plant and equipment:
Land	2,233	2,233
Buildings	68,806	64,938
Machinery and equipment	143,100	127,968
Furniture and fixtures	11,270	10,388
Total property, plant and equipment	225,409	205,527
Less: Accumulated depreciation	124,348	113,605
Property, plant and equipment, net	101,061	91,922
Certificates of deposit	1,880	5,280
Held-to-maturity Securities, Noncurrent	5,039	4,015
Note receivable, long-term	661	817
Total assets	232,854	226,974
Current liabilities:
Revolving credit facility	0	0
Accounts payable	6,178	11,370
Accrued liabilities	37,235	31,343
Total current liabilities	43,413	42,713
Deferred revenue	698	1,006
Deferred tax liabilities	8,706	7,534
Donations	$ 1,119	$ 1,662
Commitments and contingencies
Stockholders' equity:
Preferred stock, $.001 par value, 5,000,000 shares authorized, no shares issued
Common stock, $.004 par value, 100,000,000 shares authorized, 53,012,363 and 54,041,829 issued and outstanding at December 31, 2015 and 2014, respectively	$ 212	$ 216
Additional paid-in capital	0	0
Retained earnings	178,706	173,843
Total stockholders' equity	178,918	174,059
Total liabilities and stockholders' equity	$ 232,854	$ 226,974