Significant Accounting Policies - Additional Information (Detail)
|
12 Months Ended |
|
Dec. 31, 2015
USD ($)
Segment
|
Dec. 31, 2014
USD ($)
|
Dec. 31, 2013
USD ($)
|
| Significant Accounting Policies [Line Items] |
|
|
|
| Number of operating segments (segment) | Segment |
1
|
|
|
| Unrecognized tax benefits, income tax penalties and interest expense |
$ 0
|
$ 0
|
$ 0
|
| Uncertain tax positions |
0
|
0
|
|
| Accrual for interest or penalties |
0
|
0
|
|
| Accrued liability related to registration rights obligations associated with the issuance of Series B preferred stock and certain notes payable |
300,000
|
300,000
|
|
| Loss in equity-method investment |
707,000
|
940,000
|
12,000
|
| Other Assets |
|
|
|
| Significant Accounting Policies [Line Items] |
|
|
|
| Net receivable due from the joint venture |
10,000
|
10,000
|
|
| Patents |
|
|
|
| Significant Accounting Policies [Line Items] |
|
|
|
| Impairment of intangible assets |
0
|
0
|
0
|
| Research and development |
|
|
|
| Significant Accounting Policies [Line Items] |
|
|
|
| Loss in equity-method investment |
$ 707,000
|
$ 940,000
|
$ 12,000
|
| Minimum |
|
|
|
| Significant Accounting Policies [Line Items] |
|
|
|
| Fixed assets, estimated useful lives |
5 years
|
|
|
| Minimum | Software |
|
|
|
| Significant Accounting Policies [Line Items] |
|
|
|
| Intangible assets, useful life |
3 years
|
|
|
| Maximum |
|
|
|
| Significant Accounting Policies [Line Items] |
|
|
|
| Fixed assets, estimated useful lives |
7 years
|
|
|
| Maximum | Software |
|
|
|
| Significant Accounting Policies [Line Items] |
|
|
|
| Intangible assets, useful life |
5 years
|
|
|
| Letter of Credit | Restricted Cash |
|
|
|
| Significant Accounting Policies [Line Items] |
|
|
|
| Line of credit |
$ 300,000
|
|
|