Term Loans (Details) (USD $)	6 Months Ended			1 Months Ended		3 Months Ended		6 Months Ended			1 Months Ended				3 Months Ended		6 Months Ended			6 Months Ended
	Jun. 30, 2013	Jun. 30, 2014	Dec. 31, 2013	Jan. 31, 2014 General Electric Capital Corporation Term Loan [Member] payment	Mar. 31, 2013 General Electric Capital Corporation Term Loan [Member]	Jun. 30, 2014 General Electric Capital Corporation Term Loan [Member]	Jun. 30, 2013 General Electric Capital Corporation Term Loan [Member]	Jun. 30, 2014 General Electric Capital Corporation Term Loan [Member]	Jun. 30, 2013 General Electric Capital Corporation Term Loan [Member]	Jun. 30, 2014 General Electric Capital Corporation Term Loan [Member] Maximum [Member]	Apr. 30, 2014 Oxford Finance Corporation Term Loan [Member]	Dec. 31, 2012 Oxford Finance Corporation Term Loan [Member] payment	May 31, 2011 Oxford Finance Corporation Term Loan [Member] payment	Mar. 31, 2011 Oxford Finance Corporation Term Loan [Member]	Jun. 30, 2014 Oxford Finance Corporation Term Loan [Member]	Jun. 30, 2013 Oxford Finance Corporation Term Loan [Member]	Jun. 30, 2014 Oxford Finance Corporation Term Loan [Member]	Jun. 30, 2013 Oxford Finance Corporation Term Loan [Member]	Dec. 31, 2012 Oxford Finance Corporation Term Loan [Member] Maximum [Member]	Jun. 30, 2014 Oxford Finance Corporation Term Loan [Member] Minimum [Member]
Term Loans
Proceeds from term loans	$ 13,500,000				$ 12,900,000									$ 2,000,000
Principal balance		18,417,000			22,500,000
Annual interest rate on term loan (as a percent)						9.75%		9.75%							13.35%		13.35%
Number of equal monthly payments of principal plus accrued interest				30									36
Exit fee to be paid								788,000
Interest expense recognized						600,000	700,000	1,200,000	1,100,000						14,000	42,000	35,000	77,000
Transaction and exit fees and expenses recognized in interest expense						100,000	100,000	200,000	300,000
Amount of equipment financing allowed under covenants without any restriction										4,000,000
Amount of debt assumption from acquisitions requiring prior written consent under covenants																				2,000,000
Additional amount that the Company may fully utilized in equipment financing																			600,000
Full payment of the original loan											2,000,000
Principal amount of debt issued																		600,000
Number of equal monthly payments of principal plus accrued interest												36
Legal fees and expenses paid																	108,000
Future principal payments under the GECC and Oxford Term Loans
2014		4,597,000
2015		9,214,000
2016		4,606,000
Total principal payments		18,417,000			22,500,000
Less current portion		(9,200,000)	(9,451,000)
Long term obligation		$ 9,217,000	$ 13,820,000