Stockholders' Equity and Partners' Capital - Schedule of Dividends Payable (Details) - USD ($) |
3 Months Ended | 12 Months Ended | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 08, 2017 |
Sep. 15, 2017 |
Jun. 15, 2017 |
Mar. 15, 2017 |
Dec. 15, 2016 |
Sep. 15, 2016 |
Jun. 15, 2016 |
Mar. 15, 2016 |
Dec. 31, 2017 |
Sep. 30, 2017 |
Jun. 30, 2017 |
Mar. 31, 2017 |
Dec. 31, 2016 |
Sep. 30, 2016 |
Jun. 30, 2016 |
Mar. 31, 2016 |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Equity [Abstract] | |||||||||||||||||||
| Preferred stock, dividend per share (in dollars per share) | $ 0.36667 | ||||||||||||||||||
| Preferred stock, total amount | $ 2,530,000 | $ 2,530,000 | |||||||||||||||||
| Common stock, dividend per share (in dollars per share) | $ 0.18 | $ 0.18 | $ 0.18 | $ 0.18 | $ 0.18 | $ 0.175 | $ 0.175 | $ 0.175 | $ 0.18000 | $ 0.18000 | $ 0.18000 | $ 0.18000 | $ 0.18000 | $ 0.175 | $ 0.175 | $ 0.175 | $ 0.72 | $ 0.705 | |
| Common stock, total amount | $ 80,796,000 | $ 82,062,000 | $ 82,422,000 | $ 87,122,000 | $ 87,040,000 | $ 84,604,000 | $ 83,940,000 | $ 77,596,000 | $ 332,402,000 | $ 333,180,000 | $ 298,531,000 | ||||||||
| Restricted stock awards forfeitures | $ 3,300 | $ 12,000 | |||||||||||||||||