Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, beginning balance	$ 68,114	$ 68,114
Accumulated Amortization	(38,389)	(37,088)
Accumulated Impairment Loss	(19,258)	(19,258)
Net Carrying Value, ending balance	$ 10,467	$ 11,768
Trademarks
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (in years)	15 years	15 years
Gross Carrying Amount, beginning balance	$ 7,100	$ 7,100
Accumulated Amortization	(2,080)	(2,045)
Accumulated Impairment Loss	(4,179)	(4,179)
Net Carrying Value, ending balance	$ 841	$ 876
Existing technology
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (in years)	13 years	13 years
Gross Carrying Amount, beginning balance	$ 12,600	$ 12,600
Accumulated Amortization	(5,972)	(5,831)
Accumulated Impairment Loss	(4,328)	(4,328)
Net Carrying Value, ending balance	$ 2,300	$ 2,441
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (in years)	11 years	11 years
Gross Carrying Amount, beginning balance	$ 33,500	$ 33,500
Accumulated Amortization	(18,870)	(18,405)
Accumulated Impairment Loss	(10,751)	(10,751)
Net Carrying Value, ending balance	$ 3,879	$ 4,344
Reacquired rights
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (in years)	3 years	3 years
Gross Carrying Amount, beginning balance	$ 7,500	$ 7,500
Accumulated Amortization	(7,500)	(7,059)
Accumulated Impairment Loss	0	0
Net Carrying Value, ending balance	$ 0	$ 441
Patents
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (in years)	8 years	8 years
Gross Carrying Amount, beginning balance	$ 6,796	$ 6,796
Accumulated Amortization	(3,377)	(3,165)
Accumulated Impairment Loss	0	0
Net Carrying Value, ending balance	$ 3,419	$ 3,631
Other
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (in years)	2 years	2 years
Gross Carrying Amount, beginning balance	$ 618	$ 618
Accumulated Amortization	(590)	(583)
Accumulated Impairment Loss	0	0
Net Carrying Value, ending balance	$ 28	$ 35