Consolidated Statements Of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net earnings	$ 42,220,000	$ 39,940,000	$ 52,959,000
Adjustments to reconcile net earnings to net cash provided by operating activities:
Provision for depreciation	3,606,000	4,052,000	7,258,000
Intangibles amortization	83,000	2,167,000	2,630,000
Deferred income tax (benefit)	(224,000)	(121,000)	(4,001,000)
Noncash income tax expense	1,370,000
Net loss (gain) and impairment on divestiture of businesses		2,528,000
Net loss (gain) and impairment on divestiture of businesses from discontinued operations			(11,413,000)
Net gain on involuntary conversion of machinery and equipment			(2,713,000)
Loss on disposal and impairment of property, plant and equipment	322,000	163,000	248,000
Provision for doubtful accounts	7,000	458,000	70,000
Non-cash retirement plan expense	680,000	698,000	675,000
Gain on legal settlement	(2,300,000)
Other	464,000	229,000	238,000
Changes in operating accounts, net of effects of acquisition:
Accounts receivable, net	10,915,000	11,546,000	1,848,000
Inventories	(34,241,000)	6,821,000	(8,730,000)
Other assets and current assets	(2,803,000)	4,067,000	(806,000)
Accounts payable and accrued liabilities	(11,561,000)	6,066,000	(11,462,000)
Federal and state income taxes receivable/payable	1,045,000	(2,366,000)	(2,523,000)
Net cash provided by operating activities	9,583,000	76,248,000	24,278,000
Cash flows from investing activities:
Marketable securities purchased	(105,409,000)	(163,271,000)	(192,584,000)
Marketable securities - maturities and sales	161,420,000	173,060,000	132,752,000
Proceeds from divestiture of businesses, net of cash paid		9,410,000	64,033,000
Purchase of property, plant and equipment	(3,138,000)	(8,686,000)	(7,396,000)
Notes issued		(2,300,000)
Proceeds from note receivable	2,146,000
Acquisition of business, net of cash acquired	(3,733,000)
Proceeds from legal settlement	2,300,000
Proceeds from insurance settlement	807,000	2,630,000	2,104,000
Acquisition of intangible assets			(1,000,000)
Sale of property, plant and equipment	767,000	1,000	1,000
Net cash provided by (used in) investing activities	55,160,000	10,844,000	(2,090,000)
Cash flows from financing activities:
Dividends paid	(42,087,000)	(41,989,000)	(38,405,000)
Proceeds from sale of treasury stock	518,000	528,000	519,000
Other	(442,000)	(6,000)	(114,000)
Net cash used in financing activities	(42,011,000)	(41,467,000)	(38,000,000)
Net increase (decrease) in cash and cash equivalents	22,732,000	45,625,000	(15,812,000)
Cash and cash equivalents at beginning of year	56,847,000	11,222,000	27,034,000
Cash and cash equivalents at end of year	79,579,000	56,847,000	11,222,000
Supplemental disclosures of cash flow information:
Income taxes	$ 10,187,000	$ 14,968,000	$ 32,837,000