Balance Sheet Information - Intangible Assets, net (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 55,673	$ 55,673
Accumulated Amortization	(8,776)	(8,094)
Accumulated Impairment	(30,842)	(30,842)
Foreign Currency Translation Adjustments	(1,288)	(1,237)
Intangible assets, net	14,767	15,500	$ 39,264
Developed Technology
Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	26,829	26,829
Accumulated Amortization	(5,046)	(4,800)
Accumulated Impairment	(14,651)	(14,651)
Foreign Currency Translation Adjustments	(647)	(623)
Intangible assets, net	6,485	6,755
Customer relationships
Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	25,300	25,300
Accumulated Amortization	(2,803)	(2,409)
Accumulated Impairment	(14,434)	(14,434)
Foreign Currency Translation Adjustments	(525)	(511)
Intangible assets, net	7,538	7,946
Tradename
Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	3,544	3,544
Accumulated Amortization	(927)	(885)
Accumulated Impairment	(1,757)	(1,757)
Foreign Currency Translation Adjustments	(116)	(103)
Intangible assets, net	$ 744	$ 799