Goodwill and Intangible Assets - Gross Value and Net Carrying Amount (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Unamortizable intangible assets:
Gross Value	$ 18,491	$ 18,491
Accumulated Amortization	0	0
Net Carrying Amount	18,491	18,491
Developed technology | Vazculep
Amortizable intangible assets:
Gross Value	12,061	12,061
Accumulated Amortization	(11,451)	(11,248)
Net Carrying Amount	$ 610	$ 813