Summary of Significant Accounting Policies - Summary of Accounts Receivable Allowance Activity (Detail) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Accounting Policies [Abstract] | |||
| Balance at beginning of year | $ 358 | $ 112 | $ 100 |
| Additions | 246 | 12 | |
| Deductions | (95) | ||
| Balance at end of year | $ 263 | $ 358 | $ 112 |