Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 24,153	$ 7,908
Certificates of deposit	5,512	10,080
Held-to-maturity Securities, Current	14,083	12,444
Accounts receivable, net	43,001	50,024
Income tax receivable	6,239	4,702
Note receivable	25	23
Inventories, net	47,352	38,499
Prepaid expenses and other	616	533
Total current assets	140,981	124,213
Property, plant and equipment:
Land	2,233	2,233
Buildings	78,806	68,806
Machinery and equipment	158,216	143,100
Furniture and fixtures	12,783	11,270
Total property, plant and equipment	252,038	225,409
Less: Accumulated depreciation	137,146	124,348
Property, plant and equipment, net	114,892	101,061
Certificates of deposit	0	1,880
Held-to-maturity Securities, Noncurrent	0	5,039
Note receivable, long-term	657	661
Total assets	256,530	232,854
Current liabilities:
Revolving credit facility	0	0
Accounts payable	7,102	6,178
Accrued liabilities	31,940	37,235
Total current liabilities	39,042	43,413
Deferred revenue	1,498	698
Deferred tax liabilities	9,531	8,706
Donations	561	1,119
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, 52,651,448 and 53,012,363 issued and outstanding at December 31, 2016 and 2015, respectively	211	212
Additional paid-in capital	0	0
Retained earnings	205,687	178,706
Total stockholders' equity	205,898	178,918
Total liabilities and stockholders' equity	$ 256,530	$ 232,854