Segment Revenues (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Total Revenues	$ 130,550,000	$ 124,574,000
United States
Total Revenues	114,231,000	109,823,000
Canada
Total Revenues	6,935,000	6,824,000
Europe
Total Revenues	8,208,000	6,957,000
Other International
Total Revenues	1,176,000	970,000
Total International
Total Revenues	$ 16,319,000	$ 14,751,000