Summary of Significant Accounting Policies - Use of Estimates (Details) |
12 Months Ended |
|---|---|
|
Dec. 31, 2017
$ / participant
| |
| Accounting Policies [Abstract] | |
| Maximum exposure, per participant | 100,000 |
| X | ||||||||||
- Definition Loss Contingency, Self Insurance, Maximum Exposure, Per Participant No definition available.
|
| X | ||||||||||
- References No definition available.
|