Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
CURRENT ASSETS:
Cash and cash equivalents	$ 61,735	$ 56,847
Marketable securities	97,767	134,598
Accounts receivable, net	36,511	52,372
Inventories:
Finished goods	26,169	28,791
Work in process	67,690	59,580
Raw materials	6,309	5,617
Total inventory	100,168	93,988
Assets held for sale		375
Notes receivable, current	7,245	7,213
Other current assets	6,850	6,869
Total current assets	310,276	352,262
PROPERTY, PLANT AND EQUIPMENT:
PROPERTY, PLANT AND EQUIPMENT	98,601	96,094
Less allowance for depreciation	57,900	56,951
PROPERTY, PLANT AND EQUIPMENT, NET	40,701	39,143
GOODWILL	11,485	11,485
INTANGIBLE ASSETS, net	1,000	1,000
NOTES RECEIVABLE	7,019	6,966
RIGHT-OF-USE LEASE ASSETS	3,832
DEFERRED INCOME TAXES	1,069	1,088
OTHER ASSETS	1,159	1,674
Total assets	376,541	413,618
CURRENT LIABILITIES:
Accounts payable	26,510	34,100
Federal and state income taxes	3,113	1,384
Lease liabilities	539
Accrued liabilities	12,417	12,011
Total current liabilities	42,579	47,495
LEASE LIABILITIES - NON-CURRENT	3,293
COMMITMENTS AND CONTINGENCIES
STOCKHOLDERS' EQUITY
Common stock, $1 par value: Authorized: 12,000,000 shares; Issued: 7,440,518 shares	7,441	7,441
Paid-in capital	10,692	10,360
Retained earnings	326,574	362,709
Accumulated other comprehensive income	90	21
Stockholders' equity before treasury stock	344,797	380,531
Less treasury stock, at cost	14,128	14,408
Total stockholders' equity	330,669	366,123
Total liabilities and stockholders' equity	$ 376,541	$ 413,618