Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Net income	$ 959,000	$ 804,000	$ 1,467,000	$ 1,354,000
Other comprehensive income (loss):
Change in unrealized gain (loss) on marketable securities, net of tax		43,000		(35,000)
Comprehensive income	$ 959,000	$ 847,000	$ 1,467,000	$ 1,319,000