Unaudited Condensed Consolidated Statement of Equity - 6 months ended Jun. 30, 2015 - USD ($)	Total	Stockholders' Equity [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Noncontrolling Interest [Member]
Beginning balance at Dec. 31, 2014	$ 150,425,685	$ 148,083,678	$ 164,488	$ 143,474,637	$ 4,444,553	$ 2,342,007
Beginning Balance, Shares at Dec. 31, 2014	16,448,750
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 4,819,717	5,017,996			5,017,996	(198,279)
Noncontrolling interest contribution	600,841					600,841
Noncontrolling interest distribution	(821,800)					(821,800)
Stock-based compensation expense	1,234,884	1,234,884		1,234,884
Shares issued through stock plans	0	0	$ 678	(678)
Shares issued through stock plans			67,796
Ending balance at Jun. 30, 2015	$ 156,259,327	$ 154,336,558	$ 165,166	$ 144,708,843	$ 9,462,549	$ 1,922,769
Ending balance, shares at Jun. 30, 2015			16,516,546