Term Loans (Details) (USD $)	9 Months Ended	1 Months Ended	3 Months Ended		9 Months Ended			1 Months Ended		3 Months Ended		7 Months Ended	9 Months Ended			9 Months Ended
	Sep. 30, 2013	Mar. 31, 2013 GECC Term Loan payment	Sep. 30, 2013 GECC Term Loan	Sep. 30, 2012 GECC Term Loan	Sep. 30, 2013 GECC Term Loan	Sep. 30, 2012 GECC Term Loan	Sep. 30, 2013 GECC Term Loan Maximum	May 31, 2011 Oxford Term Loan payment	Mar. 31, 2011 Oxford Term Loan	Sep. 30, 2013 Oxford Term Loan	Sep. 30, 2012 Oxford Term Loan	Jun. 30, 2013 Oxford Term Loan	Sep. 30, 2013 Oxford Term Loan payment	Sep. 30, 2012 Oxford Term Loan	Jun. 30, 2013 Oxford Term Loan Maximum	Sep. 30, 2013 Oxford Term Loan Minimum
Term Loans
Proceeds from term loans	$ 13,500,000								$ 2,000,000
Principal amount of debt issued		12,900,000										600,000
Principal balance		22,500,000
Annual interest rate on term loan (as a percent)		9.75%							13.35%
Number of equal monthly payments of principal plus accrued interest		30						36
Exit fee to be paid					788,000
Interest expense recognized			682,000	423,000	1,819,000	1,315,000				36,000	40,000		99,000	137,000
Transaction and exit fees and expenses recognized in interest expense			122,000	82,000	444,000	239,000
Amount of equipment financing allowed under covenants without any restriction							4,000,000
Additional amount that the Company may fully utilized in equipment financing															600,000
Number of equal monthly payments of principal plus accrued interest													36
Legal fees and expenses paid													108,000
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
2013	233,000
2014	9,451,000
2015	9,214,000
2016	4,607,000
Total future principal payments	$ 23,505,000