| Summary of Significant Accounting Policies - Revenue Recognition (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
|---|---|---|---|
| Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | |
| Accounting Policies [Abstract] | |||
| Operating lease revenue | $ 8,189 | $ 7,238 | $ 3,409 | 
| X | ||||||||||
| 
- References No definition available. 
 | 
| X | ||||||||||
| 
- Definition The total amount of revenue recognized for the period from operating leases, including minimum lease revenue, contingent revenue, percentage revenue and sublease revenue. Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef 
 |