Property and Equipment (Details Textual) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Property and Equipment (Textual)
Depreciation expense	$ 2,119,516	$ 1,651,608	$ 4,084,790	$ 3,221,159
Depreciation included in cost of revenues and operating expenses	1,833,119	1,406,935	3,688,534	2,869,272
Depreciation on equipment held for operating lease	$ 167,987	$ 0	$ 167,987	$ 0