Agreement with New York University on Behalf of New York University Medical Center (Details)	1 Months Ended		3 Months Ended				6 Months Ended	9 Months Ended	12 Months Ended
	Jul. 31, 2018 USD ($)	Sep. 30, 2017 USD ($)	Dec. 31, 2021 USD ($)	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Jun. 30, 2021 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($) Installment	Dec. 31, 2020 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2016 USD ($) Party	Dec. 31, 2009 USD ($)	Dec. 31, 2008 USD ($)	Oct. 31, 2018 USD ($)	Jun. 30, 2017 USD ($)	Apr. 30, 2016 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
NYU Revenue Recognition [Abstract]
Maintenance services revenue			$ 0	$ 0	$ 0	$ 1,061,000	$ 1,061,000	$ 1,061,000	$ 1,061,000	$ 3,173,000
Lease Income										7,000
NYU Accounts Receivable and Contract Balances [Abstract]
Accounts receivable			0	$ 0	$ 0	$ 828,000	$ 0	$ 0	0	346,000
Perfexion Gamma Knife [Member]
Agreement With New York University [Abstract]
Lease obligation			$ 0						$ 0	89,000
Monthly lease payment																			$ 78,000
Maximum estimated site work cost		$ 1,088,000
ICON Imaging Technology [Member]
Agreement With New York University [Abstract]
Lease obligation												$ 879,000
Monthly lease payment												20,000
Gamma Knife Cobalt Reload [Member]
Agreement With New York University [Abstract]
Lease obligation															$ 833,000
Monthly lease payment															$ 30,000
NYU [Member]
Agreement With New York University [Abstract]
Term of lease agreement with NYC			7 years						7 years
Term of option			3 years						3 years
Monthly lease payment		50,000
Purchase price of gamma knife equipment		2,400,000
Number of monthly installments | Installment									41
Final lease payment amount		$ 350,000
Estimated fair value of equipment																$ 2,570,000
NYU Revenue Recognition [Abstract]
Maintenance services revenue									$ 1,061,000	3,173,000
Lease Income									982,000	2,857,000
NYU [Member] | Maintenance [Member]
NYU Revenue Recognition [Abstract]
Maintenance services revenue									$ 79,000	$ 316,000
NYU [Member] | Perfexion Gamma Knife [Member]
Agreement With New York University [Abstract]
Term of lease agreement with NYC			7 years						7 years
Extension of agreement									12 years
Cost of new equipment installed													$ 3,742,000	$ 3,742,000
NYU [Member] | Perfexion Gamma Knife, Purchase and Replacement [Member]
Agreement With New York University [Abstract]
Term of lease agreement with NYC			6 years						6 years
Lease obligation																		$ 4,700,000
Monthly lease payment																	$ 20,000
NYU [Member] | Perfexion Gamma Knife, New Installation and Related Construction Costs [Member]
Agreement With New York University [Abstract]
Term of lease agreement with NYC			2 years						2 years
Lease obligation																		$ 250,000
NYU [Member] | ICON Imaging Technology [Member]
Agreement With New York University [Abstract]
Term of lease agreement with NYC			4 years						4 years
Cost of new equipment installed												816,000
Lease obligation												879,000
Monthly maintenance agreement cost												$ 6,000
Number of parties agreed to receive payment | Party												2
Monthly lease payment											$ 30,000						$ 30,000
Final lease payment amount											350,000
NYU [Member] | Gamma Knife Cobalt Reload [Member]
Agreement With New York University [Abstract]
Term of lease agreement with NYC			30 months						30 months
Cost of new equipment installed	$ 925,000
Lease obligation	833,000
Installation costs of technology	$ 578,000
Monthly lease payment											50,000
Cobalt reload cost											$ 1,503,000