Supplemental Selected Quarterly Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Total revenues	$ 338,807	$ 351,507	$ 340,821	$ 318,270	$ 327,897	$ 340,175	$ 340,987	$ 336,184	$ 1,349,405	$ 1,345,243	$ 1,507,599
Net income	12,614	20,867	10,467	4,317	(6,110)	8,779	3,772	(2,785)	48,265	3,656	(145,351)
Net income attributable to controlling interests and available to common shareholders	$ 12,620	$ 20,864	$ 10,471	$ 4,319	$ (6,104)	$ 8,781	$ 3,767	$ (2,768)	$ 48,274	$ 3,676	$ (145,350)
Basic net (loss) income per common share (in dollars per share)	$ 0.28	$ 0.46	$ 0.23	$ 0.09	$ (0.13)	$ 0.19	$ 0.08	$ (0.06)	$ 1.06	$ 0.08	$ (3.19)
Diluted net (loss) income per common share (in dollars per share)	$ 0.28	$ 0.46	$ 0.22	$ 0.09	$ (0.13)	$ 0.19	$ 0.08	$ (0.06)	$ 1.05	$ 0.08	$ (3.19)