Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
CURRENT ASSETS:
Cash and cash equivalents	$ 11,222	$ 27,034
Marketable securities	144,252	84,457
Accounts receivable	67,089	69,101
Less allowance for doubtful accounts	1,869	1,816
Accounts receivable, net	65,220	67,285
Inventories:
Finished goods	27,242	25,200
Work in process	72,219	66,528
Raw materials and supplies	4,978	3,675
Total inventory	104,439	95,403
Assets held for sale	6,189	58,893
Other current assets	7,186	7,423
Total current assets	338,508	340,495
PROPERTY, PLANT AND EQUIPMENT:
Land and land improvements	4,985	4,933
Buildings	47,412	47,012
Machinery and equipment	51,141	49,218
PROPERTY, PLANT AND EQUIPMENT	103,538	101,163
Less allowance for depreciation	58,370	51,688
PROPERTY, PLANT AND EQUIPMENT, NET	45,168	49,475
GOODWILL	11,485	11,485
INTANGIBLE ASSETS, net	3,330	4,961
NOTES RECEIVABLE	6,750	6,534
DEFERRED INCOME TAXES	995
OTHER ASSETS	5,637	4,644
Total assets	411,873	417,594
CURRENT LIABILITIES:
Accounts payable	28,445	39,584
Federal and state income taxes	3,750	6,273
Accrued liabilities	13,092	12,244
Liabilities held for sale	210	6,253
Total current liabilities	45,497	64,354
DEFERRED INCOME TAXES		3,004
COMMITMENTS AND CONTINGENCIES
STOCKHOLDERS' EQUITY
Common stock, $1 par value: Authorized: 12,000,000 shares at December 31, 2017 and 2016; Issued: 7,440,518 shares at December 31, 2017 and 2016; Outstanding: 6,968,120 and 6,950,786 shares at December 31, 2017 and 2016, respectively	7,441	7,441
Paid-in capital	9,074	7,913
Retained earnings	364,757	350,203
Accumulated other comprehensive loss	(86)	(47)
Stockholders' equity before treasury stock	381,186	365,510
Less treasury stock, at cost, 472,398 and 489,732 shares at December 31, 2017 and 2016, respectively	14,810	15,274
Total stockholders' equity	366,376	350,236
Total liabilities and stockholders' equity	$ 411,873	$ 417,594