Property and Equipment (Details Textual) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Net property and equipment	$ 38,786	$ 41,480
Outside of the United States
Property, Plant and Equipment [Line Items]
Net property and equipment	3,343
Gamma Knife
Property, Plant and Equipment [Line Items]
Net property and equipment	$ 943
Medical equipment and facilities | Minimum
Property, Plant and Equipment [Line Items]
Useful life	3 years
Medical equipment and facilities | Maximum
Property, Plant and Equipment [Line Items]
Useful life	10 years
PBRT equipment
Property, Plant and Equipment [Line Items]
Useful life	20 years