CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
STOCKHOLDERS' EQUITY
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	25,000,000	25,000,000
Common stock, shares issued (in shares)	7,792,185	7,792,185
Common stock, shares outstanding (in shares)	7,792,185	7,792,185
Gamma Knife [Member]
Property and equipment:
Accumulated depreciation	$ 2,846,000	$ 2,637,000
Leasehold Improvements [Member]
Property and equipment:
Accumulated depreciation	$ 1,187,000	$ 1,111,000