Loan and Security Agreement (Details) (USD $)	0 Months Ended						9 Months Ended				0 Months Ended			0 Months Ended				0 Months Ended				0 Months Ended
	Jun. 11, 2014	Sep. 30, 2014	Jun. 11, 2014	May 30, 2014	Dec. 31, 2013	Oct. 07, 2014 Subsequent Event	Sep. 30, 2014 Series B-2 Shares	Jun. 06, 2014 Series B-2 Shares	May 30, 2014 Series B-2 Shares	Feb. 14, 2014 Series B-2 Shares	Jun. 11, 2014 Series B-2 Shares Maximum	Mar. 31, 2014 Series B-2 Shares Maximum	Feb. 14, 2014 Series B-2 Shares Maximum	May 31, 2014 Initial Term Loan	May 30, 2014 Initial Term Loan item	May 31, 2014 Initial Term Loan	May 30, 2014 Initial Term Loan	May 31, 2014 Second Term Loan	May 30, 2014 Second Term Loan	Jul. 10, 2014 Term Loan B	Jul. 10, 2014 Term Loan B	Dec. 31, 2014 Term Loan C Scenario, Forecast	Dec. 31, 2014 Term Loan C Scenario, Forecast
Loan and Security Agreement
Maximum borrowing limit				$ 30,000,000
Aggregate principal amount																	21,000,000				4,000,000		5,000,000
Number of payments of principal and interest payable monthly in arrears															36
Minimum aggregate net cash proceeds required to be received to make interest only payments																65,000,000	65,000,000
Number of interest and principal payments to be made if minimum required aggregate net cash proceeds are received															30
Future principal payments under the New Credit Facility
2015		4,167,000
2016		8,333,000
2017		8,333,000
2018		4,167,000
Total		25,000,000
Additional term loan that can be requested if threshold of IPO is met																			9,000,000
Threshold net cash proceed as prerequisite to request additional term loan																		65,000,000				13,000,000
Basis spread (as a percent)														9.85%
Variable interest rate, description														one-month LIBOR
Proceeds used to repay existing credit facility															9,300,000
Number of shares that can be purchased for warrants issued									10,258			491,293	718,201								4,706
Exercise price of warrant (in dollars per share)							61.42	8.00	61.42	14.004											12.75
Share issue price (in dollars per share)			$ 8.00			$ 18.25			$ 8.00
Forced conversion to common stock (in shares)	19,465,132						(448,060)
Conversion of convertible preferred stock, and associated accumulated dividends into common stock (in shares)											78,760
Expiration term of warrants																				5 years
Fair value of warrants					1,945,000												300,000				41,000
Payment of facility fees to lender															300,000
Payment of reimbursed costs to lender															$ 100,000
Debt discount amortization period															48 months