Related Party Transactions - Asset Management Agreement (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Related Party Transaction [Line Items] | |||
| Related party fee income | $ 15,838 | $ 0 | $ 0 |
| Affiliated Entity | Asset management agreement | |||
| Related Party Transaction [Line Items] | |||
| Annual management revenue in related party transaction | 20,000 | ||
| Related party fee income | 11,700 | ||
| Due from related parties | $ 1,700 | ||