401(K) Savings Plan - Additional Information (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
Defined Benefit Plan Disclosure [Line Items] | |||
Employer matching contribution expenses | $ 1.0 | $ 0.7 | $ 0.5 |
First 3% of each Participant's Contributions | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Company's matching contributions to the 401(k)plan | 100.00% | ||
Second 2% of each Participant's Contributions | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Company's matching contributions to the 401(k)plan | 50.00% |