The Company and its Significant Accounting Policies, Revenue Recognition (Details)	1 Months Ended	3 Months Ended				6 Months Ended	9 Months Ended	12 Months Ended
	Aug. 31, 2016 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 ($)	Dec. 31, 2018 USD ($)	Oct. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)
Revenue recognition [Abstract]
Present value of minimum lease payments												$ 2,447,000
Maintenance services revenue		$ 0	$ 0	$ 0	$ 1,061,000	$ 1,061,000	$ 1,061,000	$ 1,061,000	$ 3,173,000
Gamma Knife Cobalt Reload [Member]
Revenue recognition [Abstract]
Monthly lease payment											$ 30,000
ICON Imaging Technology [Member]
Revenue recognition [Abstract]
Monthly lease payment														$ 20,000
NYU [Member]
Revenue recognition [Abstract]
Minimum monthly operating lease payment	$ 30,000
Purchase price of gamma knife equipment													$ 2,400,000
Number of monthly installments | Installment								41
Monthly lease payment													50,000
Final lease payment amount													$ 350,000
Present value of minimum lease payments												$ 2,447,000
Gain on termination of contract								$ 100,000
Maintenance services revenue								$ 79,000	$ 316,000
NYU [Member] | Gamma Knife Cobalt Reload [Member]
Revenue recognition [Abstract]
Monthly lease payment										$ 50,000
NYU [Member] | ICON Imaging Technology [Member]
Revenue recognition [Abstract]
Monthly lease payment										30,000
Final lease payment amount										$ 350,000