Term Loans (Details) (USD $)	9 Months Ended		1 Months Ended		3 Months Ended		9 Months Ended			1 Months Ended			3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Jul. 31, 2012 GECC Term Loan item	Sep. 30, 2010 GECC Term Loan	Sep. 30, 2012 GECC Term Loan	Sep. 30, 2011 GECC Term Loan	Sep. 30, 2012 GECC Term Loan	Sep. 30, 2011 GECC Term Loan	Sep. 30, 2012 GECC Term Loan Maximum	Sep. 30, 2010 GECC existing equipment leases	May 31, 2011 Oxford Term Loan item	Mar. 31, 2011 Oxford Term Loan	Sep. 30, 2012 Oxford Term Loan	Sep. 30, 2011 Oxford Term Loan	Sep. 30, 2012 Oxford Term Loan	Sep. 30, 2011 Oxford Term Loan	Sep. 30, 2012 Oxford Term Loan Minimum
Term Loans
Principal amount of debt issued				$ 15,000,000								$ 2,000,000
Annual interest rate on term loan (as a percent)				9.75%	9.75%		9.75%					13.35%	13.35%		13.35%
Number of equal monthly payments of principal plus accrued interest			25								36
Origination and amendment fees paid			373,000
Exit fee to be paid							525,000
Legal fees and expenses paid			264,000									66,000
Origination, exit and transaction fees and expenses recognized in interest expense					82,000	72,000	239,000	202,000
Interest expense recognized					341,000	382,000	1,076,000	1,109,000					40,000	61,000	137,000	136,000
Amount of equipment financing allowed under covenants without any restriction									4,000,000
Repayment of remaining principal outstanding under existing equipment leases	9,000	190,000								787,000
Amount of debt assumption from acquisitions requiring prior written consent under covenants																	2,000,000
Future principal payments under the GECC and Oxford Term Loans
2012	1,966,000
2013	7,924,000
2014	4,464,000
Total future principal payments	$ 14,354,000