Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 14,562	$ 7,908
Certificates of deposit	6,232	10,080
Investments held to maturity at amortized cost	20,518	12,444
Accounts receivable, net	53,334	50,024
Income tax receivable	2,472	4,702
Notes receivable	25	23
Inventories, net	43,401	38,499
Prepaid expenses and other	820	533
Total current assets	141,364	124,213
Property, plant and equipment:
Land	2,233	2,233
Buildings	77,185	68,806
Machinery and equipment	156,932	143,100
Furniture and fixtures	12,543	11,270
Total property, plant and equipment	248,893	225,409
Less: Accumulated depreciation	133,659	124,348
Property, plant and equipment, net	115,234	101,061
Certificates of deposit	0	1,880
Investments held to maturity at amortized cost	0	5,039
Note receivable	679	661
Total assets	257,277	232,854
Current liabilities:
Revolving credit facility	0	0
Accounts payable	7,228	6,178
Accrued liabilities	36,110	37,235
Total current liabilities	43,338	43,413
Deferred revenue	1,423	698
Deferred tax liabilities	7,187	8,706
Donations	553	1,119
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, 100,000,000 shares authorized, 52,783,642 and 53,012,363 issued and outstanding at September 30, 2016 and December 31, 2015, respectively	211	212
Additional paid-in capital	0	0
Retained earnings	204,565	178,706
Total stockholders' equity	204,776	178,918
Total liabilities and stockholders' equity	$ 257,277	$ 232,854