Summary Of Significant Accounting Policies (Narrative) (Details)	3 Months Ended			12 Months Ended			36 Months Ended
	Sep. 29, 2019 USD ($)	Sep. 30, 2018 USD ($)	Jul. 01, 2018 USD ($)	Dec. 31, 2019 USD ($) segment	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2019 USD ($)
Significant Accounting Policies [Line Items]
Proceeds from sale			$ 4,000,000			$ 68,448,000
Gain on divestiture, net			$ 0			11,413,000
Checks outstanding				$ 1,308,000	$ 3,057,000		$ 1,308,000
Proceeds from sale and maturity of available for sale securities				161,420,000	173,060,000	132,752,000
Gross gains or losses related to sales of marketable securities				0	0	0
Net unrealized gains (losses) included OCI				145,000	135,000	(37,000)
Contractual maturities of marketable securities, within one year				30,669,000			30,669,000
Contractual maturities of marketable securities, beyond one year to five years				8,815,000			8,815,000
Contractual maturities of marketable securities, beyond five years to ten years				4,146,000			4,146,000
Contractual maturities of marketable securities, beyond ten years				35,103,000			35,103,000
Goodwill				15,317,000	11,485,000		15,317,000
Goodwill impairment charges							0
Goodwill, Cumulative Impairment Charges				0			0
Gross carrying amount of intangibles				2,142,000	0		2,142,000
Accumulated amortization of intangibles				83,000	0		83,000
Amortization expense				$ 83,000	2,167,000	2,630,000
Revenue recognized that was previously included in contract liability	$ 9,412,000
Number of reportable segments | segment				2
Advertising expense				$ 245,000	181,000	$ 174,000
Defense [Member]
Significant Accounting Policies [Line Items]
Impairment of Property, Plant and Equipment		$ 2,975,000
Goodwill				11,486,000			11,486,000
Impairments of Intangible Assets					46,000
Contract liabilities				1,847,000	9,579,000		1,847,000
Revenue recognized that was previously included in contract liability	$ 9,412,000			9,574,000
Unsatified performance obligations				$ 310,385,000	333,592,000		310,385,000
Housewares/ Small Appliances [Member]
Significant Accounting Policies [Line Items]
Expected prepayment utilization period				2 years
Materials Prepayments				$ 9,396,000	6,864,000		9,396,000
Change in estimate of variable consideration				0	0
Revenue recognized from performance obligations satisfied in a prior period				$ 0	0
Standard product warranty coverage period				60 days
Safety [Member]
Significant Accounting Policies [Line Items]
Goodwill				$ 3,831,000			3,831,000
Buildings [Member] | Defense [Member]
Significant Accounting Policies [Line Items]
Construction in progress				2,413,000	1,437,000		2,413,000
Machinery and Equipment [Member] | Housewares/ Small Appliances [Member]
Significant Accounting Policies [Line Items]
Construction in progress				288,000			288,000
Machinery and Equipment [Member] | Safety [Member]
Significant Accounting Policies [Line Items]
Construction in progress				$ 179,000			179,000
Minimum [Member]
Significant Accounting Policies [Line Items]
Accounts receivable, collection period				25 days
Economic use period for intangibles				2 years
Contract term				3 months
Minimum [Member] | Defense [Member]
Significant Accounting Policies [Line Items]
Holding period following recognition of revenue				7 days
Minimum [Member] | Housewares/ Small Appliances [Member]
Significant Accounting Policies [Line Items]
Standard product warranty coverage period				1 year
Minimum [Member] | Buildings [Member]
Significant Accounting Policies [Line Items]
Useful life				15 years
Minimum [Member] | Machinery and Equipment [Member]
Significant Accounting Policies [Line Items]
Useful life				3 years
Minimum [Member] | Land Improvements [Member]
Significant Accounting Policies [Line Items]
Useful life				15 years
Maximum [Member]
Significant Accounting Policies [Line Items]
Accounts receivable, collection period				60 days
Economic use period for intangibles				15 years
Contract term				24 months
Maximum [Member] | Defense [Member]
Significant Accounting Policies [Line Items]
Holding period following recognition of revenue				28 days
Maximum [Member] | Housewares/ Small Appliances [Member]
Significant Accounting Policies [Line Items]
Standard product warranty coverage period				12 years
Maximum [Member] | Buildings [Member]
Significant Accounting Policies [Line Items]
Useful life				40 years
Maximum [Member] | Machinery and Equipment [Member]
Significant Accounting Policies [Line Items]
Useful life				10 years
Maximum [Member] | Land Improvements [Member]
Significant Accounting Policies [Line Items]
Useful life				20 years
Maximum [Member] | Variable Rate Demand Notes [Member]
Significant Accounting Policies [Line Items]
Number of days to tender securites				7 days
Other Current Assets [Member] | Housewares/ Small Appliances [Member]
Significant Accounting Policies [Line Items]
Materials Prepayments				$ 4,614,000	$ 5,190,000		$ 4,614,000