Property and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Net property and equipment	$ 30,346	$ 30,418
Outside of the United States
Property, Plant and Equipment [Line Items]
Net property and equipment	$ 3,064
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