Debt - Additional Information (Detail) (USD $)	1 Months Ended	6 Months Ended	9 Months Ended				9 Months Ended			9 Months Ended				1 Months Ended	9 Months Ended		1 Months Ended	9 Months Ended			9 Months Ended		1 Months Ended	9 Months Ended	12 Months Ended	1 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended				1 Months Ended	9 Months Ended	12 Months Ended	1 Months Ended	9 Months Ended	12 Months Ended
	Apr. 10, 2013	Jun. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Oct. 31, 2012	Sep. 30, 2013 Revolving line of credit [Member]	Apr. 10, 2013 Common stock warrants [Member]	Sep. 30, 2013 Series C warrant [Member]	Sep. 30, 2013 Convertible preferred stock - Series C [Member]	Sep. 30, 2013 June 2013 credit facility [Member]	Sep. 30, 2013 June 2013 warrants [Member]	Sep. 30, 2013 June 2013 warrants [Member] Common stock warrants [Member]	Apr. 10, 2013 April 2013 junior secured promissory notes [Member]	Sep. 30, 2013 April 2013 junior secured promissory notes [Member]	Dec. 31, 2012 April 2013 junior secured promissory notes [Member]	Oct. 31, 2012 October 2012 subordinated convertible note [Member]	Sep. 30, 2013 October 2012 subordinated convertible note [Member]	Apr. 10, 2013 October 2012 subordinated convertible note [Member]	Oct. 16, 2012 October 2012 subordinated convertible note [Member]	Sep. 30, 2013 Minimum [Member]	Sep. 30, 2013 Maximum [Member]	May 31, 2013 Promissory note bearing interest at 6.25% [Member] Installment	Sep. 30, 2013 Promissory note bearing interest at 6.25% [Member]	Dec. 31, 2012 Promissory note bearing interest at 6.25% [Member]	Mar. 31, 2009 Promissory note bearing interest at 7.00% [Member] Installment	Sep. 30, 2013 Promissory note bearing interest at 7.00% [Member]	Dec. 31, 2012 Promissory note bearing interest at 7.00% [Member]	Sep. 30, 2013 October 2012 Junior secured promissory notes [Member]	Dec. 31, 2012 October 2012 Junior secured promissory notes [Member]	Jun. 30, 2013 October 2012 Junior secured promissory notes [Member]	Sep. 30, 2013 October 2012 Junior secured promissory notes [Member] Extended fourth year [Member]	Sep. 30, 2013 October 2012 Junior secured promissory notes [Member] Extended fifth year [Member]	Mar. 31, 2012 Term Loan bearing interest at 7.00% [Member]	Sep. 30, 2013 Term Loan bearing interest at 7.00% [Member]	Dec. 31, 2012 Term Loan bearing interest at 7.00% [Member]	Apr. 13, 2013 April 2012 Senior secured promissory note [Member] Installment	Sep. 30, 2013 April 2012 Senior secured promissory note [Member]	Dec. 31, 2012 April 2012 Senior secured promissory note [Member]
Debt Instrument [Line Items]
Debt instrument borrowing amount			$ 6,529,000	$ 8,075,000																			$ 400,000			$ 650,000			$ 7,500,000								$ 10,000,000
Debt instrument, interest rate																		12.00%		12.00%			6.25%	6.25%	6.25%	7.00%	7.00%	7.00%	12.00%	12.00%		13.00%	14.00%	7.00%	7.00%	7.00%	15.00%	15.00%	15.00%
Number of installments																							60			60											59
Amount paid in each installment																							7,785			13,000											238,000
Installment payment commencing date																							Jun. 01, 2008			Nov. 01, 2009											May 01, 2012
Percentage of borrowings limited to qualifying accounts receivable							75.00%
Credit facility maximum borrowing capacity							500,000				7,000,000																							500,000
Debt instrument maturity date																		Oct. 16, 2015								Nov. 01, 2014								Apr. 01, 2016
Debt instrument, payment terms																								Payable monthly through May 2013	Payable monthly through May 2013	Six monthly interest only payments starting May 1, 2009, followed by 60 equal monthly installments of $13,000 commencing November 1, 2009, with the final payment due on November 1, 2014.	Payable monthly through November 2014	Payable monthly through November 2014	Payable monthly through October 2015	Payable monthly through October 2015					Payable monthly through April 2016	Payable monthly through April 2016		Payable monthly through April 2017	Payable monthly through April 2017
Non-refundable loan fees																																					625,000
Installment payment final date																																					2017-04-01
Warrants issued to lender for of purchase preferred stock										191,000
Warrants exercise price										$ 7.846
Warrant expiration period										The Series C Warrant would expire, unless exercised, on the earlier to occur of April 2022 or one year after the Company successfully completes a Qualified IPO
Fees amount									625,000						485,000	270,000
Fair value of Series C Warrant									306,000
Termination fee, percentage																					0.00%	3.00%
Convertible note repayment terms																																						35 days
Total repayment debt																																						9,451,000
Principal amount of repayment																																						9,139,000
Principal amount of repayment, accrued interest																																						34,000
Termination fee payment																																						278,000
Debt instrument borrowing terms																													The October 2012 Junior Secured Promissory Notes have an initial term of three years and can be extended for an additional two years in one year increments. During the initial three-year term, the October 2012 Junior Secured Promissory Notes bear interest at 12% per annum. If the term of the October 2012 Junior Secured Promissory Notes is extended an additional year, the interest rate increases to 13% during the fourth year. If the term of the October 2012 Junior Secured Promissory Notes is extended for an additional two years, the interest rate is 14% during the fifth year. Interest on the October 2012 Junior Secured Promissory Notes is payable monthly through the initial maturity date of the loan which is October 2, 2015 or through any extension period. The principal and all unpaid interest are due on the maturity date, as may be extended.
Agent Fee percentage			5.00%																										5.00%
Additional fee percentage																													1.00%
Unpaid Agent Fee															172,000														261,000
Additional costs related to legal fees															66,000
Warrants issued to purchase common stock funded principal percentage																													15.00%
Value of common stock in a sale of the Company or an initial public offering		70.00%				70.00%						70.00%																	70.00%
Fair value of Common Stock Warrants																													282,000
Exercise price of the Common Stock Warrants			8.40									8.40																	8.40
Covenant requirements minimum cash balance																													5,000,000
Additional debt cash balance																													2,000,000
Increase in amount available under loan agreement	5,000,000
Additional debt issued under amendment	4,950,000
Debt issued in partial consideration for cash	3,700,000
Debt issued in partial conversion for cancellation of principal balance	1,250,000
Amount borrowed under amended loan agreement																														7,500,000	12,450,000
Accrued interest on promissory notes		74,000	74,000
Warrants exercise price percentage			70.00%
Exercise price of warrants as percentage of common stock			70.00%
Common stock warrants issued to purchase common stock percentage			20.00%										10.00%
Fair value of Common Stock Warrants			465,000
Convertible debt instrument, face value				8,804,000	41,860,000														1,250,000
Convertible debt, fair value																		1,360,000	1,360,000
Debt instrument, additional borrowings														2,500,000	2,500,000
Promissory Notes issued														3,750,000															3,750,000
Gain on extinguishment of debt			49,000
Debt discount								113,000
Fair value of Additional Common Stock Warrants issued														352,000	352,000
Funds borrowed			3,700,000												4,250,000
Additional unpaid Agent Fee, percentage			5.00%
Deferred finance costs	24,000		195,000		261,000												87,000
Amount permit to draw											5,000,000
Credit facility expiry date											Jun. 30, 2014
Credit facility accrued interest											10.00%
Credit facility fee											2.00%						5.00%
Credit facility financing-related costs and primarily legal fees											8,000
Warrants expire date												Jun. 14, 2023
Fair value of the Warrants at the date of issuance as deferred financing cost			$ 435,000