Property and Equipment (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Property and Equipment (Textual)
Depreciation expense	$ 2,070,007	$ 2,119,516	$ 4,144,514	$ 4,084,790
Depreciation included in cost of revenues and operating expenses	1,902,611	1,833,119	3,632,422	3,688,534
Depreciation on equipment held for operating lease	$ 0	$ 167,987	$ 0	$ 167,987