401(k) Profit Sharing Plan - Additional Information (Details) - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Defined Contribution Plan Disclosure [Line Items] | |||
| Profit sharing plan information | The Company’s employees participate in the Company’s 401(k) profit sharing plan (the “401k Plan”) that covers all employees eighteen years of age or older who have completed three months of employment. | ||
| Employee contribution on compensation, maximum | 100.00% | ||
| Percentage of employees' annual contribution, eligible for employers match | 50.00% | 50.00% | 50.00% |
| Percentage of employees' annual contribution matched | 5.00% | 5.00% | 5.00% |
| Employer contribution amount | $ 900,000 | $ 700,000 | $ 500,000 |
| Deferred Profit Sharing | |||
| Defined Contribution Plan Disclosure [Line Items] | |||
| Employer contribution amount | $ 0 | $ 0 | $ 0 |