| Fair Value of Financial Assets - Additional Information (Details) | Sep. 30, 2018 | Dec. 31, 2017 | 
|---|---|---|
| Fair Value Disclosures [Abstract] | ||
| Discounted cash flow include a discount rate | 15.00% | 15.00% | 
| X | ||||||||||
| 
- Definition Discounted cash flow discount rate. No definition available. 
 | 
| X | ||||||||||
| 
- References No definition available. 
 |