(17) Quarterly Financial Data (Details) (USD $)	3 Months Ended																12 Months Ended
	Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Quarterly Financial Information Disclosure [Abstract]
Revenue (a)	$ 22,487,683	[1]	$ 17,089,013	[1]	$ 16,466,201	[1]	$ 19,368,072	[1]	$ 25,426,942	[1]	$ 18,856,390	[1]	$ 19,628,008	[1]	$ 18,959,262	[1]	$ 75,410,969	$ 82,870,602	$ 82,843,746
Gross profit	16,766,610		12,208,096		11,587,960		14,186,230		19,243,475		14,049,801		13,943,379		14,117,037		54,748,896	61,353,693	61,404,795
Net loss	$ (2,346,276)		$ (3,568,051)		$ (6,620,586)		$ (2,449,408)		$ (6,114,804)		$ (5,398,176)		$ (5,889,039)		$ (5,966,265)		$ (14,984,321)	$ (23,368,283)	$ (35,375,621)
Basic net loss per share	$ (0.05)		$ (0.08)		$ (0.14)		$ (0.05)		$ (0.13)		$ (0.12)		$ (0.13)		$ (0.13)		$ (0.32)	$ (0.50)	$ (0.78)
Diluted net loss per share	$ (0.05)		$ (0.08)		$ (0.14)		$ (0.05)		$ (0.13)		$ (0.12)		$ (0.13)		$ (0.13)		$ (0.32)	$ (0.50)	$ (0.78)

[1] Due to cash collections of previously reserved accounts receivable balances, the Company recorded a benefit of approximately $0.7 million during both the years ended December 31, 2012 and 2011, respectively. These amounts are included within revenues in each respective period in the accompanying consolidated statements of operations.