Equity Method Investments (Schedule of Supplemental Operations Information) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue	$ 6,429,000	$ 8,177,000
Net income	1,006,000	$ 1,693,000
StockCross [Member]
Revenue	4,014,000
Gross profit	285,000
Net income	$ 246,000