Reconciliation of Segment Operating Income (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Reconciliation Of Segment Operating Income Details
Total operating income									$ 8,442,056	$ 7,347,006
Interest expense, net									868,507	565,212
Other expense, net									76,846	167,397
Consolidated income before taxes									7,496,703	6,614,397
Net income	$ 545,000	$ 1,473,000	$ 3,267,000	$ 565,000	$ 440,000	$ 1,208,000	$ 2,710,000	$ 436,000	$ 5,850,998	$ 4,793,525