Subsequent Event (Details) $ in Thousands		3 Months Ended
	Apr. 09, 2021 USD ($) loan_facility	Mar. 31, 2021 USD ($) note	Dec. 31, 2020 USD ($)
Subsequent Event [Line Items]
Number of debt instruments | note		5
Short-term debt and finance lease obligations		$ 6,669
Current portion of debt		782	$ 1,157
First Credit Facility
Subsequent Event [Line Items]
Proceeds used to refinance domestic Gamma Knife debt, finance leases and associated costs		$ 1,600
Subsequent Event | Fifth Third Bank Credit Agreement | London Interbank Offered Rate (LIBOR)
Subsequent Event [Line Items]
Basis spread on variable rate	3.00%
Subsequent Event | Fifth Third Bank Credit Agreement | Line of Credit
Subsequent Event [Line Items]
Debt instrument (in years)	5 years
Line of credit facility, maximum borrowing capacity	$ 22,000
Number of debt instruments | loan_facility	3
Fixed charge coverage ratio	1.25
Debt to EBITDA ratio	3.0
Subsequent Event | First Credit Facility
Subsequent Event [Line Items]
Proceeds used to refinance domestic Gamma Knife debt, finance leases and associated costs	$ 6,800
Remaining available amount that can be borrowed	1,100
Subsequent Event | First Credit Facility | Line of Credit
Subsequent Event [Line Items]
Line of credit facility, maximum borrowing capacity	9,500
Subsequent Event | Second Credit Facility | Line of Credit
Subsequent Event [Line Items]
Line of credit facility, maximum borrowing capacity	5,500
Subsequent Event | Third Credit Facility | Line of Credit
Subsequent Event [Line Items]
Line of credit facility, maximum borrowing capacity	$ 7,000