CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (LOSS) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ 89,368	$ (129,346)	$ 543,969	$ (125,524)
Other comprehensive gain (loss)
Unrealized gain (loss) on marketable equity securities		70,812		(21,777)
Comprehensive gain (loss)	$ 89,368	$ (58,534)	$ 543,969	$ (147,301)