Property and Equipment (Details Textual) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Property and Equipment (Textual)
Depreciation expense	$ 1,545,166	$ 1,326,757	$ 3,092,511	$ 2,503,759
Depreciation included in inventory	$ 1,171,242	$ 986,549	$ 2,343,975	$ 2,082,964