Real Estate Investments - Pro Forma (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings (loss) per common share from continuing operations:
Basic -- as reported									$ 0.19	$ (0.21)	$ (0.01)
Diluted -- as reported									0.19	(0.21)	(0.01)
Earnings (loss) per common share:
Basic -- as reported	$ (0.08)	$ 0.03	$ (0.02)	$ 0.25	$ (0.37)	$ 0.10	$ 0.01	$ 0.04	0.19	(0.21)	0
Diluted -- as reported	$ (0.08)	$ 0.03	$ (0.02)	$ 0.25	$ (0.37)	$ 0.10	$ 0.01	$ 0.04	$ 0.19	$ (0.21)	$ 0
Broadmoor Austin Associates [Member]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pro forma revenue										$ 612,649	$ 618,119
Pro forma income (loss) from continuing operations										(36,704)	(7,371)
Pro forma net income (loss) available to common shareholders										$ (43,594)	$ (13,669)
Earnings (loss) per common share from continuing operations:
Basic -- as reported										$ (0.17)	$ 0.04
Basic -- as pro forma										(0.21)	(0.04)
Diluted -- as reported										(0.17)	0.04
Diluted -- as pro forma										(0.21)	(0.04)
Earnings (loss) per common share:
Basic -- as reported										(0.21)
Basic -- as pro forma										(0.24)	(0.08)
Diluted -- as reported										(0.21)
Diluted -- as pro forma										$ (0.24)	$ (0.08)