Intangibles - Finite and Indefinite Lived Intangibles (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Historical Cost	$ 91,638,000	$ 91,216,000
Accumulated Amortization	65,191,000	64,710,000
Customer lists
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Historical Cost	51,108,000	51,828,000
Accumulated Amortization	51,108,000	50,768,000
License agreements
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Historical Cost	2,884,000	733,000
Accumulated Amortization	770,000	733,000
Developed technology
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Historical Cost	7,483,000	7,608,000
Accumulated Amortization	6,642,000	6,563,000
Patents
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Historical Cost	5,521,000	5,500,000
Accumulated Amortization	5,521,000	5,497,000
Other
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Historical Cost	1,163,000	1,162,000
Accumulated Amortization	1,150,000	1,149,000
Trademarks
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Historical Cost	23,479,000	24,385,000
Other Segments | Trademarks
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)	587,000	583,000
Indefinite Lived Intangible Assets, Impairment Losses After Tax	$ 435,000	$ 431,000