Stockholders' Equity and Partners' Capital - Summary of Dividends Declared (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 9 Months Ended
Aug. 13, 2019
May 30, 2019
Feb. 28, 2019
Sep. 30, 2019
Jun. 30, 2019
Mar. 31, 2019
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Sep. 30, 2019
Sep. 30, 2018
Equity [Abstract]                      
Preferred stock, dividend per share (in USD per share) $ 0.375 $ 0.375 $ 0.375                
Preferred stock, total amount $ 2,587 $ 2,588 $ 2,588 $ 2,587 $ 2,588 $ 2,588 $ 2,588 $ 2,588 $ 2,588    
Common stock, dividend per share (in USD per share) $ 0.625 $ 0.625 $ 0.625 $ 0.6250     $ 0.6250     $ 1.8750 $ 2.4250
Common stock, total amount $ 62,322 $ 56,318 $ 54,254 $ 62,322 $ 56,318 $ 54,254 $ 53,546 $ 77,143 $ 78,581