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Notes Payable - Additional Information (Detail) - USD ($) |  | 1 Months Ended | 9 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | --- | ---
Jun. 30, 2013 | Mar. 31, 2015 | Apr. 30, 2014 | Sep. 30, 2015 | Dec. 31, 2014 | Jun. 30, 2014 | Dec. 31, 2013 | Dec. 31, 2010
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Amortization of financing costs and discounts |  |  |  | $ 636,000 |  |  |  |
Notes payable |  |  | $ 1,000,000 |  |  |  |  |
Promissory note agreed to convert |  |  | 114,369 |  |  |  |  |
Accrued interest paid |  |  | $ 39,000 |  |  |  |  |
Notes payable and accounts payable, total |  |  |  | $ 950,000 |  |  |  |
Warrant exercisable as a percentage of shares issued |  |  |  | 300.00% |  |  |  |
Settlement agreement payment cash paid |  |  |  | $ 265,000 |  |  |  |
Cash settlement exchange for retiring notes |  | $ 132,000 |  |  |  |  |  |
Difference amount of notes payable and amount paid to retire |  | $ 133,000 |  |  |  |  |  |
License agreement and miscellaneous other obligation |  |  |  |  |  |  | $ 23,000 |
Debt instrument, increase, accrued interest |  |  |  | 50,000 |  |  |  |
Other creditors holding |  |  |  | 50,000 |  |  |  |
Other creditors outstanding principal |  |  | 95,000 |  |  |  |  |
Other creditors outstanding principal |  |  |  | 29,000 |  |  |  |
Accrued interest were repaid by cash |  |  |  | 13,000 |  |  |  |
2013 Securities Purchase Agreement |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Notes payable |  |  |  | $ 1,000,000 |  |  |  |
2013 Promissory Note |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Convertible notes payable current | $ 1,000,000 |  |  |  |  |  |  |
Proceeds from issuance of preferred stock | $ 1,000,000 |  |  |  |  |  |  |
Percentage of accrued interest |  |  |  |  |  | 5.00% |  |
Short term debt maturity date |  |  |  | Jun. 20, 2014 |  |  |  |
Proceeds from security purchase agreement |  |  |  | $ 364,000 |  |  |  |
2009 Convertible Notes |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Convertible notes payable current |  |  |  | $ 426,000 |  |  |  |
Percentage of accrued interest |  |  |  | 24.00% |  |  |  | 15.00%
Short term debt maturity date |  |  |  | Sep. 30, 2010 |  |  |  |
Accrued interest outstanding |  |  |  |  |  |  | $ 396,000 |
Outstanding convertible note payable |  |  |  |  | $ 0 |  |  |
Debt and capital lease obligations |  |  |  | $ 194,000 |  |  |  |
Conversion period |  |  |  | 3 years |  |  |  |
Debt instrument, face amount |  |  |  | $ 20,000 |  |  |  |
Debt instrument, increase, accrued interest |  |  |  | $ 29,000 |  |  |  |
2009 Convertible Notes | CA Warrant |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Warrant percentage |  |  |  | 20.00% |  |  |  |
Stock price of warrants |  |  |  | $ 2.44 |  |  |  |
Warrant expiration date |  |  |  | Sep. 30, 2019 |  |  |  |
2009 Convertible Notes | PA Warrant |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Warrant percentage |  |  |  | 9.00% |  |  |  |
2009 Convertible Notes | 2013 Securities Purchase Agreement |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Convertible notes payable current |  |  | 426,000 |  |  |  |  |
Accrued interest outstanding |  |  | $ 422,000 |  |  |  |  |
Side Agreement Notes |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Convertible notes payable current |  |  |  | $ 249,000 |  |  |  |
Promissory note agreed to convert |  |  |  | 192,341 |  |  |  |
Series B Preferred Stock |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Proceeds from security purchase agreement |  |  |  | $ 636,000 |  |  |  |
Series B Preferred Stock | 2013 Promissory Note |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Preferred stock shares issued | 1,851 |  |  |  |  |  |  |
Series C Preferred Stock |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Promissory note agreed to convert |  |  | 771,458 |  |  |  |  |
Common Class A |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Promissory note agreed to convert |  |  | 192,865 | 230,859 |  |  |  |
Conversion price of common stock |  |  |  | $ 2.44 |  |  |  |
Exchanged warrants, in share |  |  |  | 123,433 |  |  |  |
Stock price of warrants |  |  |  | $ 2.44 |  |  |  |
Warrant exchanged |  |  |  |  | 3,052,608 |  |  |
Common stock issued for placement agent commission |  |  |  | 34,715 |  |  |  |
Common stock exercise of warrants purchase of share |  | 32,675 |  |  |  |  |  |
Common stock exercise of warrants purchase price per share |  | $ 2.44 |  |  |  |  |  |
Common Class A | 2013 Securities Purchase Agreement |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Notes payable |  |  |  | $ 950,000 |  |  |  |
Promissory note agreed to convert |  |  |  | 389,437 |  |  |  |
Diluted stock outstanding, percentage |  |  |  | 10.00% |  |  |  |
Common Class A | 2009 Convertible Notes |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |
Promissory note agreed to convert |  |  |  | 20,205 |  |  |  |
Conversion price of common stock |  |  |  | $ 2.44 |  |  |  |
Exchanged warrants, in share |  |  | 985,229 |  |  |  |  |
Settlement agreement with conversion of common stock |  |  |  | $ 265,000 |  |  |  |
Common stock conversion price |  |  |  | $ 2.44 |  |  |  |
Financing closing cost |  |  |  | $ 1,200,000 |  |  |  |

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