Notes Payable - Additional Information (Detail) - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Debt Instrument [Line Items] | |||
| Line of credit facility description | Upon entering into the 2014 Credit Facility, the Company was obligated to make monthly, interest-only payments on any term loans funded under the 2014 Credit Facility until December 1, 2014 and, thereafter, to pay 36 consecutive, equal monthly installments of principal and interest from January 1, 2015 through December 1, 2017. As per the terms of the agreement, in June 2014, upon the completion of the Company’s IPO, the term of monthly, interest-only payments | ||
| Credit facility maturity date | Dec. 01, 2017 | ||
| Line of credit facility annual interest rate | 8.10% | ||
| Line of credit facility additional fee percentage | 6.00% | ||
| Credit facility default amount | $ 300,000 | ||
| Term Loan A [Member] | |||
| Debt Instrument [Line Items] | |||
| Charges to interest expense of debt outstanding | 500,000 | ||
| 2014 Credit Facility [Member] | |||
| Debt Instrument [Line Items] | |||
| Covenants under credit facility | 0 | ||
| 2014 Credit Facility [Member] | Secured Debt [Member] | |||
| Debt Instrument [Line Items] | |||
| Interest expense on credit facility | $ 500,000 | $ 800,000 | $ 900,000 |
| Effective annual interest rate | 10.80% | ||
| Credit Facility [Member] | |||
| Debt Instrument [Line Items] | |||
| Sale of voting equity threshold | 50.00% | ||