Goodwill and Other Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
GOODWILL AND OTHER INTANGIBLE ASSETS
Definite-lived, Gross Carrying Amount	$ 26,145	$ 42,215
Definite-lived, Accumulated Amortization	(11,831)	(28,380)
Definite-lived, Net Carrying Amount	14,314	13,835
Total other intangible assets, Gross Carrying Amount	35,215	51,285
Accumulated Impairment	(4,953)	(4,953)
Total other intangible assets, Net Carrying Amount	18,431	17,952
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)	0	0
Amortization expense	$ 6,000	5,000	$ 6,700
Minimum
GOODWILL AND OTHER INTANGIBLE ASSETS
Amortized period of intangible assets	2 years
Maximum
GOODWILL AND OTHER INTANGIBLE ASSETS
Amortized period of intangible assets	12 years
Trade name
GOODWILL AND OTHER INTANGIBLE ASSETS
Indefinite lived, Gross Carrying Amount	$ 9,070	9,070
Indefinite lived, Accumulated Impairment	(4,953)	(4,953)
Indefinite lived, Net Carrying Amount	4,117	4,117
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)	0	0	$ 200
Customer lists
GOODWILL AND OTHER INTANGIBLE ASSETS
Definite-lived, Gross Carrying Amount	16,879	32,772
Definite-lived, Accumulated Amortization	(5,845)	(22,726)
Definite-lived, Net Carrying Amount	$ 11,034	10,046
Customer lists | Minimum
GOODWILL AND OTHER INTANGIBLE ASSETS
Amortized period of intangible assets	4 years
Customer lists | Maximum
GOODWILL AND OTHER INTANGIBLE ASSETS
Amortized period of intangible assets	10 years
Trade name
GOODWILL AND OTHER INTANGIBLE ASSETS
Definite-lived, Gross Carrying Amount	$ 255	255
Definite-lived, Accumulated Amortization	(176)	(151)
Definite-lived, Net Carrying Amount	$ 79	104
Amortized period of intangible assets	10 years
Other intangible assets | Maximum
GOODWILL AND OTHER INTANGIBLE ASSETS
Amortized period of intangible assets	19 years
Patents and other intangibles
GOODWILL AND OTHER INTANGIBLE ASSETS
Definite-lived, Gross Carrying Amount	$ 9,011	9,188
Definite-lived, Accumulated Amortization	(5,810)	(5,503)
Definite-lived, Net Carrying Amount	$ 3,201	$ 3,685