Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 12,209	$ 7,908
Certificates of deposit	9,832	10,080
Investments held to maturity at amortized cost	22,303	12,444
Accounts receivable, net	58,483	50,024
Income tax receivable	669	4,702
Notes receivable	25	23
Inventories, net	40,125	38,499
Prepaid expenses and other	1,083	533
Total current assets	144,729	124,213
Property, plant and equipment:
Land	2,233	2,233
Buildings	75,912	68,806
Machinery and equipment	152,165	143,100
Furniture and fixtures	12,058	11,270
Total property, plant and equipment	242,368	225,409
Less: Accumulated depreciation	130,505	124,348
Property, plant and equipment, net	111,863	101,061
Certificates of deposit	240	1,880
Investments held to maturity at amortized cost	0	5,039
Note receivable	695	661
Total assets	257,527	232,854
Current liabilities:
Revolving credit facility	0	0
Accounts payable	9,367	6,178
Dividends payable	5,797	0
Accrued liabilities	38,087	37,235
Total current liabilities	53,251	43,413
Deferred revenue	1,295	698
Deferred tax liabilities	6,855	8,706
Donations	1,142	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, 53,008,136 and 53,012,363 issued and outstanding at June 30, 2016 and December 31, 2015, respectively	212	212
Additional paid-in capital	0	0
Retained earnings	194,772	178,706
Total stockholders' equity	194,984	178,918
Total liabilities and stockholders' equity	$ 257,527	$ 232,854