Equity - Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator - Basic:
Net income (loss)	$ (19,618)	$ 18,930	$ (11,330)	$ 28,786
Private perpetual preferred unit distributions	(1,047)	(234)	(2,097)	(468)
Net income (loss) attributable to non-controlling interests	7,872	(7,609)	5,129	(11,554)
Earnings allocated to unvested shares	(25)	(13)	(36)	(20)
Net income (loss) attributable to common stockholders - basic	(12,818)	11,074	(8,334)	16,744
Numerator - Diluted:
Net income (loss)	(19,618)	18,930	(11,330)	28,786
Private perpetual preferred unit distributions	(1,047)	(234)	(2,097)	(468)
Earnings allocated to unvested shares	(25)	(13)	(36)	(20)
Net income (loss) attributable to common stockholders - diluted	$ (20,690)	$ 18,683	$ (13,463)	$ 28,298
Denominator:
Weighted average shares outstanding - basic (in shares)	175,433,000	176,796,000	178,029,000	176,495,000
Operating partnership units (in shares)	107,951,000	121,335,000	109,986,000	121,605,000
Effect of dilutive securities:
Stock-based compensation plans (in shares)	0	0	0	0
Weighted average shares outstanding - diluted (in shares)	283,384,000	298,131,000	288,015,000	298,100,000
Earnings per share:
Basic (in USD per share)	$ (0.07)	$ 0.06	$ (0.05)	$ 0.09
Diluted (in USD per share)	$ (0.07)	$ 0.06	$ (0.05)	$ 0.09
Antidilutive securities (in shares)	109,649	411,019	254,772	205,851