Financial Liabilities - Additional Information (Detail) (USD $)	0 Months Ended	1 Months Ended	3 Months Ended	9 Months Ended			0 Months Ended		3 Months Ended		9 Months Ended			1 Months Ended		1 Months Ended	9 Months Ended		0 Months Ended		1 Months Ended
	Aug. 14, 2013	Mar. 31, 2014	Mar. 31, 2014	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014 Bluehill I D	Aug. 07, 2013 Hercules Technology Growth Capital Inc	Oct. 30, 2012 Hercules Technology Growth Capital Inc	Sep. 30, 2014 Hercules Technology Growth Capital Inc	Sep. 30, 2013 Hercules Technology Growth Capital Inc	Sep. 30, 2014 Hercules Technology Growth Capital Inc Installment	Sep. 30, 2013 Hercules Technology Growth Capital Inc	Oct. 30, 2012 Hercules Technology Growth Capital Inc Maximum	Mar. 31, 2014 Bank Term Loan	Oct. 30, 2012 Secured Notes Hercules Technology Growth Capital Inc	Mar. 31, 2014 Opus Bank	Sep. 30, 2014 Opus Bank Installment	Jun. 30, 2014 Opus Bank	Aug. 08, 2014 RevolvingCreditFacility	Mar. 31, 2014 RevolvingCreditFacility	Mar. 31, 2014 RevolvingCreditFacility Opus Bank Bank Term Loan
Debt Instrument [Line Items]
Amount borrowed under term loan				$ 13,925,000	$ 6,022,000											$ 10,000,000
Borrowing capacity under credit facility																10,000,000
Amount drawn under credit facility																4,000,000		2,000,000
Repaid on revolving credit facility																			1,700,000
Net proceeds from term loan and credit agreement		7,800,000
Credit facility and term loan maturity date																	Mar. 31, 2017
Credit facility and term loan interest description																	Bear interest at a floating rate equal to the greater of (i) the prime rate plus 2.75% and (ii) 6.00%.
Additional interest above base rate											7.75%					2.75%
Minimum percentage of interest on credit facility and term loan facility																6.00%
Credit facility and term loan payment terms																	Interest is payable monthly beginning on May 1, 2014. Also, under the existing terms of the Credit Agreement at September 30, 2014, the principal balance of the Term Loan is payable in 24 equal monthly installments beginning on May 1, 2015
Number of monthly installments											30						24
Debt instrument, first date of principal payment																	May 01, 2015
Debt issuance cost								600,000								170,000
Warrants issued to purchase common stock																100,000
Warrant exercise price							$ 7.10									$ 9.90
Private placement warrant estimated volatility	91.57%															92.09%
Warrants exercise term (in years)							5 years
Private placement warrant risk free interest rate	1.08%															1.73%
Private placement warrant fair value	4,000,000						500,000									800,000
Payments of debt issuance costs																					900,000
Write off of discounts on loan				600,000										500,000
Deferred charges																				400,000
Term loan													10,000,000
Term loan, additional advance															10,000,000
Net proceeds from debt offering								6,900,000
Initial advance of the debt note received from lender at the time of issuance								7,500,000
Term loan, maturity date											Nov. 01, 2015
Term loan, interest rate term											incurred interest at the greater of (i) the prime rate plus 7.75% and (ii) 11.00%
Interest rate									11.00%		11.00%
Term loan, payment term											Interest on the Secured Note was payable monthly beginning on November 1, 2012, and the principal balance was payable in 30 equal monthly installments beginning on May 1, 2013
Payment of financing costs											150,000
Percentage of financing cost credited to the company if all advances are repaid on maturity											50.00%
Additional loan fee payable to lender											1,000,000
Number of installments to pay fees											3
Debt instrument, additional fees, date of first installment payment											Oct. 30, 2013
Debt interest expense									0	200,000	400,000	1,100,000
Warrants issued to purchase common stock							99,208
Additional interest expense			1,600,000
Write off of deferred cost				900,000
Prepayment fees on advances, net				$ 100,000
Percentage of ownership						100.00%